Experimental study of thermal characteristics for a novel ventilation roof with composite phase change material (VRCPCM)

Abstract

A phase change material particle (PCMP) was prepared by vacuum adsorption method, with the binary eutectic mixture of myristic acid and tetradecanol as phase change material (PCM) and expanded vermiculite (EVMT) as porous adsorption materials. Then PCMPs were pressed into composite phase change plates (CPCP) for the outside layer of roof to store the heat passively. The active cooling storage was provided by the cold water in the seamless steel pipe and the iron box containing binary eutectic mixture of lauric acid and tetradecanol on the indoor side. Combined with the ventilation roof, a novel ventilation roof with composite phase change material experimental hut was constructed. The cold storage performance test was conducted under the two strategies which were regularly opened ventilation layer at certain time and timing cooling while regularly opened ventilation layer. The first strategy result showed that CPCP effectively reduced the temperature of the outer surface of the roof and the ventilation layer was turned on at night, which could effectively reduce the indoor air peak temperature. The second strategy result under the active cooling condition showed that the indoor PCM could absorb the heat of the indoor air and reduce the indoor temperature and the indoor temperature fluctuation range.