地板辐射采暖盘管泄漏传热模型及数值模拟

Heat Transfer Model and Numerical Simulation of Coil Pipe Leakage in Radiant Floor Heating

低温热水地板辐射采暖盘管对系统的安全运行具有重要意义。由于室内装修等施工作业造成地板辐射采暖盘管缺陷,从而导致系统运行时泄漏事故的发生,为减低此类事故的危害性及时判定泄漏点位置对防止泄漏的扩散尤为重要。通过分析地板辐射采暖盘管泄漏特性,建立盘管泄漏过程传热传质模型,并利用FLUENT软件模确定盘管泄漏前后地板和水泥层表面温度场分布情况。研究结果表明:(1)盘管泄漏初期,水泥层表面原始温度场迅速被破坏,而整个地板表面变化较弱;随着泄漏时间的加长,地板表面温度场也造成破坏,可以通过其表面温度场明显判断泄漏点位置。(2)泄漏影响区域主要由三个区域组成,在泄漏口附近较大区域为1区恒定高温区,温度梯度变化较小;临近1区外为2区温度梯度区,温度梯度变化剧烈;受泄漏影响较弱区域为3区地板稳态温度区,其温度主要由原始地板温度场控制。

The radiant floor heating coil pipe of low temperature hot water has important meaning for the system of safe operation.As coil pipe defect of radiant floor heating caused by construction work of indoor decoration etc,thus causing leakage accident occurred in system operation,decreasing harmfulness of this kind accident and judging situation of leaking point in time is particularly important for preventing leakage diffusion.Through analysis coil pipe leakage characteristics of radiant floor heating,coil pipe leakage process of heat and mass transfer model was established,and temperature field distribution of floor and cement layer surface of pre and post coil pipe leakage were determine dusing FLUENT software simulation.Research results show：（1） The original temperature field of cement layer surface is quickly destroyed in initial coil pipe leakage,while the changes of floor surface are weaker;with the leakage time lengthen,the temperature field of floor surface are destroyed,which could obviously judge the leakage position.（2） Leakage effect areas are mainly composed by three areas,the large area near the leakage hole is 1 area,which is the constant high temperature area and had small changes in temperature gradient;2 area near the outside of 1 area is temperature gradient area,temperature gradient change greatly;3 area which is floor steady state temperature area has weak effect by leakage,the temperature is mainly controlled by the original floor temperature field.