Solar Energy Utilization Characteristics Of A Solar Building Integrated Wall

With the vigorous development of construction industry and the substantial improvement of human living standards,residents have put forward higher requirements for indoor thermal environment,and the demand for building heating energy consumption in cold seasons will also greatly increase.Building energy consumption is an important cause of greenhouse gas emissions and global warming.The application of renewable energy in building energy consumption can not only reduce the consumption of fossil energy,but also alleviate greenhouse gas emissions and mitigate global warming.Solar energy is a kind of renewable energy with extremely wide application,which has the advantages of cleanness,abundant reserves and low cost,and has great utilization potential in buildings.Developing the solar building integration technology,combining solar energy application technology with building envelope structure,is an important development trend of solar energy application in buildings.This paper investigated the current research status of solar energy utilization in buildings in domestic and abroad,and designed a kind of solar building integrated wall with simple structure.For the integrated solar building wall,not only should it have the ability to effectively introduce solar energy into the room and avoid indoor heat from dissipating to the outside in cold seasons,but it should also can well prevent solar heat from entering the room in hot seasons.In recent years,although there have been many research results in improving the thermal insulation performance of envelope structures,it is still difficult to meet the requirements of variable thermal insulation performance of walls.A favorable solar building integration technology should comprehensively consider its various performance parameters.Therefore,this study designed a kind of solar building integrated wall with simple structure,which could reduce the effective thermal resistance of the wall during the heating season and improve the utilization efficiency of solar heating,while it could increase the effective thermal resistance of the wall during the air conditioning season,reduce the outdoor heat entering the room and reduce the air conditioning load.Experiments and simulations of the wall were carried out under climatic conditions in the cold season.The results indicate that the heat transfer amount of the solar building integrated wall increased with the increase of the solar irradiance,whereas the solar thermal utilization efficiency decreased.Increasing the circulating water flow can increase the heat transfer amount of the wall and solar thermal utilization efficiency,thus change the effective thermal resistance of the wall.Under the studied conditions,the heat transfer amount and solar thermal utilization efficiency reached 1530.21 W and 63.8%,respectively.The circulating water flow does not need to be greater than 200 L/(h·m~2).The area ratio of the thermal radiation plate to solar collector has a great influence on the heat transfer amount of the wall and the solar thermal utilization efficiency.Under simulated conditions,when the area ratio increased from 0.5 to 2.0,and the circulating water flow was 200 L/(h·m~2),the heat transfer amount increased from 672.37 W to 1831.62 W,and the solar thermal utilization efficiency increased from 16.8%to 45.8%.Increasing the area of thermal radiation plate is beneficial to improving the solar thermal utilization efficiency.