Study On Preparation And Heat Transfer Characteristics Of Phase Change Wall

As an energy material,phase change materials are often used in energy storage because of their high energy storage density,latent heat of phase change,stable performance and excellent cost performance.Adding phase change materials into traditional cement wall can improve the heat storage capacity of the building wall,reduce indoor temperature fluctuations,reduce air conditioning load,and have better energy saving significance.In this paper,46# paraffin and sodium stearate were used as phase change materials,and the phase change wall was prepared by direct mixing method and layered insertion method.The phase change gypsum board was prepared by direct immersion method,and their heat transfer performance was studied separately.In this paper,the common solid-liquid phase change materials are summarized and summarized,and the thermal property values are compiled.Different phase change walls were prepared by direct mixing method and layered insertion method,and the heat transfer performance was studied.The experimental results show that compared with the ordinary wall,the temperature reduction rate of the phase change wall prepared by the direct mixing method and the layered insertion method is 26% and 35%,respectively.Compared with the heating rate of 7.9 °C / h of ordinary wall,the heating rate of phase change wall prepared by direct mixing method and layered insertion method was 3.9 °C / h and 2.6 °C / h,respectively.The energy-saving effect of the phase-change wall prepared by the composite material is better than that of the phase-change wall prepared by the single phase-change material.The energy-saving effect of the wall prepared by the layered insertion method is better than that of the wall prepared by the direct mixing method.The thermal conductivity of the phase change material layer in the phase change wall is 0.136 W/(m·K).When the phase change gypsum board is prepared by direct immersion method,the best immersion conditions are: soaking time 1h,soaking temperature 70 °C.When tannic acidlauric acid is a phase change material,the ratio of the gypsum board to the phase change material is the highest when the ratio is 7:3;when the tannic acid-stearic acid is the phase change material,the ratio is 7:3 and 6:4.The retention rate of the gypsum board to the phase change material is approximately the same.The thermal conductivity of the phase change gypsum board was calculated by heat transfer theory to be 0.112 W/(m·K).At the end of this paper,a brief overview of the development direction of phase change materials applied to building walls is made,which makes the phase change materials and building walls better combined.