Heating Performance Study On Phase Change Trombe Wall Pattern Solar Building

The past few years has witnessed the extensive researches on phase change energy storage technology in the field of architecture in China.The research results show that heat-storage and discharge characteristics of phase change materials(PCM)can effectively optimize indoor thermal comfort.Besides,the use of renewable energies can make efficient contribution to alleviating the trend of world energy exhaustion.Therefore,in this thesis,PCM,which store heat during daytime and release heat during nighttime,are added to Trombe wall to improve indoor thermal comfort by raising night temperature and dropping indoor temperature fluctuation.Through theoretical calculation and experimental test,complex of 55% capric acid and 45% lauric acid is chosen as the phase change material,whose phase transition temperature and latent heat of phase change are 21.33℃ and 133.4kJ/kg respectively.Phase change Trombe wall pattern solar laboratory houses are built in Mianyang with electrothermal film heating phase change Trombe wall,to measure the internal temperature and skin temperature of phase change Trombe wall,interlayer temperature,glass window temperature and indoor air temperature under the condition of opening,shutting and opening and shutting combination of tuyere.Experimental findings are as follows.The opening of tuyere is beneficial to higher indoor temperature during daytime and the shutting of tuyere is available to store heat.And opening and shutting combination is the best way to enhance indoor thermal comfort.However,in the process of heating,significant differences happen to Trombe height direction,leaving uneven wall melt.After a full heat storage,it takes three days to release all the heat accumulated in the phase change Trombe wall.Based on dynamic network analysis,a two-dimensional unsteady heat transfer state space model of phase change Trombe wall pattern solar building is built,using MATLAB programming to compare the air interlayer temperature measuredin the situation of tuyere opening,heating surface temperature and indoor temperature with analog data.Measured data are in line with analog data,which proves the validity of this heat transfer model.The verified two-dimensional unsteady heat transfer state space model of phase change Trombe wall pattern solar building is employed to simulate the different solar energy distribution in three areas,Jiuquan,Beijing and Shenyang.With the usage of phase change Trombe wall pattern solar building,the optimal portfolios of phase-transition temperature and phase change layer thickness are23℃-5cm,23℃-5cm and 21℃-5cm respectively.In addition,when the phase change layer thickness of Trombe wall is ≥7cm,phase change temperature and solar radiation intensity have a tiny influence on the indoor temperature of phase change Trombe wall pattern solar building and the phase change interface in Trombe wall should be fixed at5 cm in thickness direction.