冷热工况下混凝土辐射地板的蓄释热性能分析

Thermal storage and release characteristics of concrete radiant floor under cooling and heating conditions

为了阐明混凝土辐射地板的蓄释热性能,从时间常数的角度出发,通过实验分析混凝土辐射地板在蓄热、释热过程中温度及热量的响应特征。结果表明:供暖工况的时间常数快于供冷工况,混凝土辐射地板温度更易趋于稳定。当供水流量为6 L/min、1倍时间常数时,在环境温度(26.0±1.0)℃、供水温度22.1℃的供冷工况下,120 mm厚辐射地板试块的平均蓄冷能力和释冷能力分别为21.6 W/m^2和11.7 W/m^2;在环境温度(16.5±1.0)℃、供水温度29.8℃的供暖工况下,辐射地板试块的平均蓄热和释热能力则分别为83.7 W/m^2和40.2 W/m^2。供水流量对混凝土辐射地板的蓄释热能力影响较小,但通过改变供水温度能够明显提高混凝土辐射地板的蓄释热能力以及变化速率。随着供水温度和罩内空气温度之差的增大,累计蓄热量呈指数关系上升,累计释热量则呈线性关系上升。该研究结果可为混凝土辐射系统的设计、运行控制策略的制定提供依据。

In order to clarify the thermal storage and release characteristics of the concrete radiant floor,the temperature and thermal response characteristics of the concrete radiant floor in the process of thermal storage and release were analyzed from the perspective of time constant.The results showed that the time constant in the heating condition was faster than that in the cooling condition,and the temperature of concrete radiant floor was easier to tend to be stable.When the water supply flow was 6 L/min and the time constant was 1,the average cooling storage capacity and release capacity of the 120 mm thick radiant floor test block were 21.6 W/m^2 and 11.7 W/m^2 respectively under the condition of the ambient temperature(26.0±1.0)℃and the water supply temperature 22.1℃.The thermal storage capacity and release capacity of the radiant floor specimen were 83.7 W/m^2 and 40.2 W/m^2 respectively under the condition of the ambient temperature(16.5±1.0)℃and the water supply temperature 29.8℃.The water supply flow had little influence on the thermal storage and release characteristics of concrete radiant floor,but the thermal storage and release capacity and the change rate were significantly improved by changing the water supply temperature.With the increase of the temperature difference between the water supply and the air in the hood,accumulated thermal storage increased exponentially,and the accumulated thermal release increased linearly.The results can provide a basis for the design and operation control strategy of concrete radiation system.