低温电热辐射地板蓄传热特性研究

Study on Heat Storage and Heat Transfer Characteristics of Low Temperature Electrically Heated Radiant Floor

为探究发热元件为电热膜和发热电缆的低温电热辐射地板的蓄传热特性,建立了电热膜地板和发热电缆地板的二维非稳态传热数值计算模型,分析了发热元件埋深、供热强度、运行时间、发热电缆间距对地板蓄传热特性的影响。结果表明,发热元件埋深为2.0cm、7.5cm时,发热电缆地板的蓄热量分别是电热膜地板的4.2倍、1.2倍,埋深为13.0cm、15.0cm时,二者蓄热量相当,埋深较浅时,系统关闭时发热电缆地板表面热流明显大于电热膜地板,前者的蓄热性能更优。随着供热强度的增大、系统运行时间的增长、发热电缆间距的减小,地板上表面平均温度、地板蓄热量、放热量均呈增大趋势,但地板蓄热量占总供热量的比例却降低。

In order to explore the heat storage and heat transfer characteristics of the floor under different kinds of heat source,a two-dimensional unsteady heat transfer numerical model of the low-temperature electrically heated radiant floors using the heating film and the heating cable was established.The effects of burying depth of heating element,heating intensity,running time and spacing of heating cable on the performances of heat storage and heat transfer of the floor are analyzed.Results show that when the heating element is buried at 2.0cm and 7.5cm,the heat storage capacity of the floor with heating cable is 4.2 times and 1.2 times that of the floor with heating film,respectively.When the heating element is buried at 13.0cm and 15.0cm,the difference is not obvious.When the buried depth is shallow,the heat storage performance of the floor with heating cable is better.With the increase of heating intensity,and system running time,and the decrease of heating cable spacing,the average surface temperature of the floor,heat storage and heat release of floor all increase,but the proportion of floor heat storage in the total heat supply decreases.