空气载能辐射空调优化与控制机理研究

Radiant air-conditioning systems are being paid more and more attention with the continuous improvement of people's living standard. At present, radiant air conditioning systems mainly employ liquid as the energy carrier and storage, including the radiant cooling ceiling systems, the capillary tube radiant systems, the water-coiling precast thin plate radiant heating systems and so on. However, the high installing and operation cost, the complicated structures, the condensation water problems and troublesome maintenance are the common characteristics of all of the above liquid radiant systems.Then a new kind of radiant air-conditioning system scheme is proposed in this subject firstly. The circulating air is used as the energy carrier and storage in this new radiant system. Without the use of liquid, a large sum of installation cost will be cut down,the relative simple structures make it easier for the further maintenieance and the condensation problems will also be solved well. With the help of the theory of thermodynamics and hydrodynamics and the methods of theoretical analysis, computer simulation and experimental research ,we would begin with the research on the thermodynamics, hydrodynamics and heat and mass transfer mechanism of the serious processes such as the thermal performance contrast to other systems, the system roof scheme and the air distribution form, IAQ and indoor thermal comfort, condensation process and so on. And then we would build a serious of mathematics model to find out the optimal scheme of indoor thermal comfort and the control of IAQ, and to study the energy-saving operation control strategy, which could provide the theory basis and technological support for the operation control of the air carring and storing raditant air-conditioning systems.

辐射型空调系统愈来愈引起人们的关注，现有的辐射型空调系统主要以液体为能量载体，即液体载能。大致有盘管与金属顶板组合系统、毛细管辐射系统、水盘管预制薄型板辐射采暖系统等。但是，上述的辐射空调施工维护较复杂，初装及使用成本较高，能耗也较大。本课题首次提出了一种利用循环空气作为能量载体的空气载能辐射空调系统方法，此系统具有施工维护简单，成本低廉以及节能效果更好的特点。本课题将以热力学和流体动力学理论为基础，通过理论分析、计算机仿真模拟与实验研究相结合的方法，从系统热力学性能对比、系统顶板方案及气流组织形式、IAQ与室内热舒适、结露过程等环节的热力学、流体力学、传热传质机理等方面着手，建立起相关的数学模型，寻找室内热舒适及空气品质控制的最优方案,研究系统节能运行的控制策略,从而为空气载能辐射空调系统优化设计和运行控制提供理论依据和技术支持。

相较于传统的空调系统而言，辐射空调系统具有高舒适性和高节能性，然而现有的辐射型空调系统主要以液体为能量载体，在工程应用过程中仍存在成本过高，且后期维护困难等问题。空气载能辐射空调系统作为一种以空气为载能媒介、孔板或其它材质平板为辐射板的一种新型的辐射末端系统，兼有孔板送风系统和辐射末端系统的特点，且安装维护方便，系统经济简单，适用范围更广。.本课题通过理论分析、计算机仿真模拟与实验研究相结合的方法，针对空气载能辐射空调系统展开研究。首先分析空气载能辐射空调系统的实际传热过程，并采用修正系数法得出空气载能辐射空调系统夏季负荷的修正系数为0.75，冬季热负荷修正系数为0.8, 确定了该新型辐射末端条件下空调系统的负荷简便计算方法。基于传热学计算出不同孔板温度和传热温差下辐射孔板的辐射传热量，并得出该新型末端的辐射传热简化公式，可反映出孔板辐射传热量与孔板温度、传热温差之间的关系，通过分析得出了空气载能辐射孔板末端总传热比常规辐射空调的末端多20％左右。另外通过模拟研究了末端孔板表面空气临界露点温度随孔板开孔率、送风温度以及送风速度的变化，得出孔板表面空气临界露点温度分布范围在11.8-14.5℃之间，相比相同室内热湿参数的常规辐射空调系统，露点温度可低6.3-9.0℃。同时通过对该辐射末端系统的热舒适展开实地问卷调查研究，得出了空气载能末端系统夏季房间温度设定为29℃，冬季设定为14℃时，仍能满足大部分人群的热舒适性要求，这对于实现夏热冬冷地区冬夏空调一体化具有重要的理论支撑。另外在本项目的研究中，对室内人体呼吸周围的微环境进行分析探讨，研究了人体呼吸过程中室内空气稳定性，这对于将来进一步研究空气载能辐射空调下多模态热舒适和通风有效性具有重要意义。