LAUSR

Abstract In order to improve the thermal performance of Trombe wall, the mixture of 55% decanoic acid and 45% lauric acid as a kind of PCM was chosen to integrate with it. The article presents a test of properties of this PCM and an experimental study on a small-scale integrated PCM Trombe wall. Two periodic heat input modes simulate the periodically varying solar radiation absorbed by the absorber. Its melting temperature and latent heat are 21.33°C and 133.4 KJ/kg, respectively and its volume expansion rate is 7.94%. The experimental results show that the integrated PCM Trombe wall can increase indoor air temperature by 0.82°C∼1.88°C for low heat input mode and 1.75°C∼3.27°C for high heat input mode. Besides, two-dimensional heat transfer along the height and thickness directions of PCM wall results in large temperature difference in these two directions even if the absorber surface is heated evenly. There exists the irregular-shape liquid/solid interface. The PCM above the liquid/solid interface can be completely melted while that below the liquid/solid interface is always in the solid state. Therefore, it is suggested that the PCM with the suitable melting temperature, a wide range of phase change temperature and high latent heat should be chosen.