内嵌管式围护结构间歇供冷房间热过程及热环境响应特性与优化调控

The heat storage effect of tubes-embedded building envelope cooling system makes intermittent operation fully demonstrate its energy-saving characteristics. However, lack of scientific understanding of the response characteristics of thermal environment of intermittently cooled room hinders the reasonable application of intermittent control. The purpose of the project is to study thermal behavior of intermittently cooled room by embedded radiant cooling system and clarify the dynamic response characteristics of indoor thermal environment as well as its influencing factors. The study will be performed from the following aspects: (1) The mathematical model of the thermal behavior of intermittent cooled room by embedded radiant cooling system with auxiliary ventilation will be established, and it will be validated by field measured data. The empirical formula of the mixed convection heat transfer coefficient between the cold surface and its surrounding air will be determined by experiment. (2) The dynamic response characteristics of thermal environment in intermittent cooled room will be studied to draw the quantitative evaluation of thermal storage capacity of building envelope and obtain the heat storing/releasing characteristics of tubes-embedded envelope. The dynamic response of indoor thermal environment to intermittent operation will be established. (3) From the perspectives of geometry and thermal properties of the tubes-embedded building envelope and other passive walls, the sensitive analysis on the influencing factors of thermal environment response will be conducted to identify the significant factors. (4) On/ff time and run-time of system will be optimized, and the optimal intermittent regulation basing on the trade-offs between the two objectives of energy efficiency and thermal comfort will be established. The results will provide a theoretical guidance for the intermittent operation of tubes-embedded building envelope cooling system.

内嵌管式围护结构供冷系统的蓄热效应使间歇运行充分发挥节能特性，缺乏对间歇供冷房间热环境响应特性的科学认识，阻碍了间歇调控的合理应用。本课题旨在通过研究内嵌管式围护结构间歇供冷房间热过程，阐明房间热环境动态响应特性、基本规律及影响因素。研究内容有：（1）建立辅助通风系统的内嵌管式围护结构间歇供冷房间热过程的数学模型，采用实验方法确定冷辐射表面混合对流换热系数的经验公式，采用实测数据验证数学模型的有效性；（2）研究间歇供冷房间热环境动态响应特性，给出围护结构蓄冷能力与冷滞时间的定量评价以及围护结构动态蓄放热规律，建立房间热环境对间歇运行的动态响应；（3）从供冷构件及被动式墙体的几何结构和热物性能层面，对房间热环境动态响应的影响因素进行敏感性分析，找出显著影响因素；（4）优化系统启停时间和运行时间，建立舒适及节能双目标优化的间歇调控机制。研究结果为内嵌管式围护结构供冷系统的间歇调控提供理论指导。

内嵌管式围护结构供冷系统的蓄热效应使间歇运行充分发挥节能特性，缺乏对间歇供冷房间热环境响应特性的科学认识，阻碍了间歇调控的合理应用。本课题通过研究内嵌管式围护结构间歇供冷房间热过程这一基础科学问题，透彻分析研究了间歇供冷房间热环境动态响应特性、基本规律及影响因素，为间歇调控提供理论指导。. 本课题建立了辅助通风系统的内嵌管式围护结构间歇供冷下房间热过程的数学模型，确定了冷辐射表面对流换热系数的经验关联式；在此基础上，研究了供冷构件间歇运行房间热环境动态响应特性，得出围护结构蓄冷能力与冷滞时间的定量评价以及围护结构动态蓄放热规律，并对房间热环境动态响应的影响因素进行了敏感性分析。优化系统启停时间和运行时间，建立了舒适及节能双目标优化的间歇调控机制。. 主要结论如下：（1）实测研究表明内嵌管式辐射供冷系统间歇运行是可行的，由于围护结构具有一定的蓄冷量，间歇运行不会引起室内热环境参数大幅度波动，不会引起人体的热不舒适感。（2）利用热电类比理论建立了内嵌管式辐射供冷房间热过程的综合RC网络模型，开发了内嵌管式围护结构供冷房间热过程及热环境动态模拟软件。（3）内嵌管式围护结构供冷，仅有45%-60%的冷量用于室内热环境控制，供冷时长越长， 供冷构件蓄冷量越大，建议在满足室内热舒适的前提下尽量选择较短的供冷时长。（4）夜间预冷和日间供冷对室内空气温度、单位面积水侧供冷量及供冷构件热流密度影响不大，从转移电力高峰负荷的角度，建议选择夜间预冷。（5）供水管间距与埋管深度的变化对于供冷构件蓄冷量的影响不大。 （6）齐齐哈尔地区、沈阳地区、西安地区、上海地区、广州地区最佳供冷时长分别是四小时、六小时、八小时、十小时、十四小时。（7）相同的供冷时长下采用水泵的频繁启停控制能够增大房间的供冷量。. 所得研究结果可为内嵌管式围护结构供冷系统的间歇运行调控提供理论指导，并为供冷围护结构及被动式墙体的优化设计提供理论参考。