Study On Thermal Performance Of Solar Heat Storage Walls

With the rapid development of China’s economy,the proportion of building energy consumption in the total energy consumption of society is increasing year by year.Using new energy to replace traditional fossil energy is an important way to reduce energy consumption and carbon emissions in buildings.China has abundant solar energy resources,but there is a mismatch between supply and demand in solar energy utilization and energy consumption time.To this end,this paper proposes a new type of thermal collector wall structure that can make full use of solar energy,and conducts a study on its performance influencing factors and practical application effects,the specific research content and results are as follows:(1)A numerical model of the new collector heat storage wall is established,model verification of the numerical model is carried out based on experimental data,and numerical simulation of the heat storage and discharge process is carried out under typical working conditions.The simulation results show that the heat storage and heat release processes were carried out for 7 h and 17 h with the boundary conditions of 300 W/m~2 and 10℃.The simulation results show that there is a temperature stratification between the heating space and the air layer during the heat storage process,and the maximum temperature difference between the upper and lower part of the air layer at the end of the heat storage exceeds 13℃.The maximum temperature difference between the upper and lower part of the indoor temperature does not exceed 0.7℃,and the temperature difference is small.(2)The heat storage and exothermic processes of walls with different air layer thickness,heat storage panel thickness,and vent size were calculated at different solar radiation intensities,and according to the simulation results,the radiation intensity size has the most obvious effect on the thermal performance of the wall,in the exothermic process,the radiation intensity of 500 W/m~2 is 2°C to 7.8°C higher than the average indoor temperature of 300 W/m~2.The smaller the thickness of the heat storage panel,the higher the indoor temperature in the heat storage process.The smaller the thickness of the heat storage panel,the higher the indoor temperature in the heat storage process,but the temperature of the exothermic process drops significantly and the temperature fluctuation is larger.The smaller the vent,the better the heat insulation effect of the exothermic process of the wall.(3)The practical application effects of the new heat-collecting thermal storage wall and the traditional Trombe wall in Qinhuangdao area were compared.The results show that the new wall can maintain the indoor temperature at a certain high level after the long-term multiple heat storage and exothermic process,and can delay the arrival of peak temperature,which is better than the traditional Trombe wall in reducing the indoor temperature stratification,insulation performance,and the uniformity of flow rate of indoor flow field.