自力式套管封装相变墙体排热系统及相变简化模型研究

A Pipe-encapsulated Phase Change Material (PCM) Wall System for Self-activated Heat Removal and Development of the Simplified PCM Model

建筑能耗日益增加,新型建筑节能技术越来越受到人们的重视。在建筑空调领域,提高建筑围护结构的热特性能够明显减少室内负荷,降低建筑能耗。本文提出了一种新型自力式套管封装相变排热节能墙体系统。该墙体系统充分利用夜间天空辐射冷却实现墙体内热量的自动转移。针对该墙体内嵌入的套管相变材料建立了4R2C热容热阻简化相变传热模型,并利用遗传算法对模型参数进行辨识。进一步搭建了套管相变材料的实验平台,并将模拟结果与实验结果进行对比。结果表明,4R2C简化相变模型能够准确的模拟套管相变材料的传热特性,内套管表面温度与热流平均误差分别为0.45℃和14.4%。简化相变模型能够很好与墙体热模型耦合,实现自力式套管封装相变墙体系统热特性与节能特性的集成模拟。

With the increase of building energy consumption,new building energy-saving technologies are receiving more and more attention in recent years.In the field of building air conditioning,improving the thermal performance of building envelope can significantly decrease the indoor load and building energy consumption.This paper presents a new pipe-encapsulated phase change material(PCM)wall system for self-activated heat removal.This system can make full use of the nocturnal cooling radiation technology to realize the self-activated transfer of the stored heat in PCM.A simplified thermal model with two thermal capacity and four thermal resistances(4 R2 C)for the pipe-encapsulated PCM embedded in the wall is developed.The model parameters are identified by GA.An experimental platform is set up for the measurement of thermal performance of this pipe-encapsulated PCM.The thermal performance predicted by this simplified model is compared with the experimental measurements for validation.The results show that the 4 R2 C simplified model can accurately predict the thermal performance of the pipe-encapsulated PCM.The mean error of surface temperature and heat flow of the inner pipe are respectively 0.45℃and 14.4%.Therefore,it is verified that the simplified PCM model can be well coupled with the thermal model of wall to simulate the thermal and energy-saving performance of the pipe-encapsulated phase change material(PCM)wall system for self-activated heat removal.