地板辐射采暖传热模型修正及散热因素分析

楼板向下散热量和内外墙体温度差异较大时,利用现有的模型计算地板辐射采暖系统地面温度分布导致误差较大.通过分析内外墙和楼板对地板辐射采暖系统传热的影响,找出零热面模型的不足,修正了传热模型,并分析影响采暖盘管的散热因素.研究结果表明, (1)内外墙体的壁温相差大时,零热面模型误差偏大,则内外墙边界条件设为第一类边界条件较合理;(2)楼板下表面设为由辐射换热等效的第三类边界条件较合理;(3)管径增大导致地板表面温度增加趋势减小.管间距、热水温度增大导致供热区域地板表面温度分布呈周期性变化逐渐明显.且管间距变大导致其周期增加、热水温度变大导致其振幅增加.选择合适的地板层材料才能保证舒适的地面温度.

Model Correction and Affected Factors Analysis of heat transfer of floor heating system

High error in calculating the heat transfer of floor heating system can be introduced by existing models, considering the heat transfer of the floor slab and different temperature between interior wall and exterior wall. A modified calculation model of heat transfer of floor heating system was proposed, analyzed the influence of the interior or exterior wall and the floor slab, and discussed the disadvantages of zero heat-flux models. The affected factors of heat transfer of floor heating system were studied by using the new model. The results show that, (1) Certain temperature is the best boundary condition between interior wall and exterior wall, for the case the temperature are different between interior wall and exterior wall, and high error can be introduced by zero heat-flux model. (2) Heat radiation is the best boundary condition of under surface of floor slab. (3) The temperature growth of floor surface decrease, with increasing the diameter of pipeline. The temperature periodicity distribution of floor surface more clearly, with increasing the distance between pipelines or hot water temperature. The length of periodicity increases, with increasing the distance between pipelines. The swing length of periodicity increases, with increasing the hot water temperature. It is also found that it is important to floor surface layer material.