Investigation On The Performance Of Phase Change Energy Stoarge Wallboard Based On Encapsulating Phase Change Materials By Capillary

Most of buildings in China today belong to the buildings of high energy consumption. The energy consumption of per unit area building in China is 3 to 5 times that in developed countries. Reducing building energy consumption has become an urgent task. The energy consumption proportion of wall is the largest in buildings. When phase change materials (PCMs) take places phase change, it absorbs or releases heat. The indoor load can be transferred by adding some suitable PCMs. It can reduces indoor load, reduces indoor temperature fluctuation and improves thermal comfort.A new phase change energy storage wallboard is built using encapsulating paraffin or sodium sulfate decahydrate by capillary with gypsum The energy storage effect and effective factors of phase change wallboard are investigated experimently. The main work is described as the following:The temperature response of actual wall is measured in some representative days of summer. The temperature average value of test results is used as the basis of environmental temperature. The heat transfer processes of phase change energy storage wallboard are analyzed. The experiment simulation conditions are determined through experimental tests.Paraffin and sodium sulfate decahydrate are chosen as phase change energy storage materials. The paraffin mixtures and sodium sulfate decahydrate mixtures are prepared according to the temperature of phase change energy storage.The feasibility and reliability of encapsulating phase change materials by capillary is discussed. Some kinds of phase change energy storage wallboards are made. The effect of capillary tube diameter, capillary tube thickness, thermal conductivity, the content of phase change materials and thermal conductivity of phase change materials on total thermal resistance, heat capacity and phase change time of phase change energy storage wallboard through calculation are analyzed.The temperature response of one side of phase change energy storage wallboard is tested while the temperature of the other side of the wallboard is under the conditions that controlled by high and low temperature alternating test chamber. The effect of phase change materials, phase change temperature, phase change materials content and capillary tube diameter on wallboard energy storage is studied, compared with pure gypsum board.Three kinds of phase change energy storage building models are built using gypsum, paraffin or sodium sulfate decahydrate encapsulating by capillary.The temperature response of the phase change energy storage building model and the pure gypsum building model are tested under three conditions, which are closed all day, ventilated all day and ctosed during the day but ventilated at night under the natural environment m summer.The main research conclusions:Capillary encapsulating phase change material by capillary is simple and reliable. The phase change temperature range of paraffin mixture and sodium sulfate decahydrate mixture can be changed by change the mixture ratio. Thermal conductivity and content of phase change materials had important effect on the phase change storage wallboard's total thermal resistance. But capillary tube diameter, thickness, thermal conductivity and phase change temperature of phase change materials have less effect on the phase change energy storage wallboard's total thermal resistance. Heat capacity of phase change energy storage wallboard is decided by phase change latent heat and content of phase change materials. Phase change energy storage combined with night ventilation could save more energy.