Study On Dynamic Heat Transfer Characteristics And Seasonal Adaptability Of Pcm Integrated In Thermal Energy-storing Building Wallboard

In recent years,the latent heat energy storage of phase change materials has attracted much attention.The energy storage characteristics of phase change materials can be used to build building envelope,which can better coordinate the contradiction between time and space of energy supply and further improve the building comfort.However,the heat transfer characteristics and seasonal adaptability of phase change energy storage walls need to be further studied.In this paper,the phase change temperature recommended for phase change materials in phase change energy storage building walls is obtained by combining numerical simulation and experimental test,and the dynamic heat transfer characteristics of phase change energy storage building walls and the adaptability of phase change walls in different seasons are analyzed.The main work contents are as follows:A method for determining the appropriate phase change temperature of the phase change energy storage wall corresponding to the orientation and type of the building wall is proposed,and the appropriate phase change temperature of the phase change energy storage building wall in summer is determined.Numerical simulation was carried out for different types of phase change energy storage walls.The internal temperature fluctuation rule of the wall was used to determine the standard,and the latent heat utilization rate of phase change materials and the temperature fluctuation of phase change layer were considered.The suitable phase change temperature of phase change material in phase change energy storage wall decreases gradually with the position of phase change material in the wall from the outside to the inside.An experimental test method for heat transfer characteristics of phase change energy storage wall is presented.An artificial environment simulation experiment platform was designed and built to simulate the outdoor environment in summer.The heat transfer characteristics of the phase change energy storage wall were tested.In the simulation,the ambient temperature obtained from the experimental test is loaded as the boundary condition,and compared with the experimental test results,which proves that the simulation model is reasonable and effective.The heat transfer characteristics of different types of phase change energy storage building walls are analyzed.The insulation performance of the phase change wall is the best,and the temperature attenuation and hysteresis of the phase change wall are the best.The temperature attenuation of the wall with phase change increased by 68.1%,the temperature peak lag time increased by 2h,and the wall heat storage coefficient increased by 20.2%.The attenuation factor of temperature of sandwich phase change wall increased by 86.5%,and the temperature peak lag time increased by 2h.The temperature attenuation ratio of the inner wall with phase change increased by 145.7%,and the temperature peak lag time increased by 2.76 h.According to the seasonal adaptability of phase change wall,the optimum temperature,placement and filling thickness of phase change materials were obtained.Phase change materials were selected at 30℃,position 4 and thickness of10 mm in summer,and at 14℃,position 3 and thickness of 10 mm in winter,with the best seasonal adaptability.