双层相变蓄能辐射地板传热特性实验研究

An experimental study on a radiant floor system with double-layered phase change materials

本文构建了一种可用于供暖和供冷两种工况的相变蓄能辐射地板系统,该系统包含蓄冷和蓄热两层石蜡相变材料,相变点分别为18℃和34℃,针对该相变地板蓄冷和蓄热层上下相对位置的变化,通过实验研究了在供暖水温45℃和供冷水温15℃两种工况下,这两种不同结构的相变地板的传热特性,以及相变层对找平层、地板层等结构层的影响。结果表明,该相变地板系统可用于供热和供冷两种工况,两种结构模式下,不同结构层在蓄能过程中温度变化特性均相近,但释能过程温度变化特性区别较大。结构的变化对实验箱体内气温在供暖时影响较大,而在供冷时影响不大。综合供冷供暖两种工况,从系统冷量和热量的传递结果考虑,蓄热层在上、蓄冷层在下的结构传热性能更优,可缓解地板温度过快下降带来的热舒适性差及结露问题。

This paper reports a newly proposed phase change material based radiant floor system. The system consists of two phase change material layers with one for cold storage for space cooling and the other for heat storage for space heating. The phase change temperatures of the two materials are respectively 18 ℃ and 34 ℃. Two designs of the floor systems, A and B, were studied. The Design A had the cold storage layer placed on top of the heat storage layer; whereas the Design B placed the heat storage material on top of the cold. An experimental system was used to compare the two designs, which used a flow of water（120 L/h flowrate） with inlet temperatures of 45 ℃ and 15 ℃ for heating and cooling respectively. The results showed that the designs had a great influence on the indoor air temperature under the heating operations but exerted very little influence on the indoor air temperature under the cooling operations. This implied that the Design B had a better heat transfer performance than the Design A.