Study on solar energy utilization characteristics of a solar building integrated wall

•Heating performance of a solar building integrated wall was studied.•Numerical model was validated experimentally and applied to parametric study.•Changing operating conditions could adjust the heating performance.•Adjusting water flow of collector could change effective thermal resistance of wall.•Area ratio of radiation plate to collector notably affected the heating performance. This study proposed a solar building integrated wall in which a solar hot water circulation system was installed. The wall was provided with a solar collector and a thermal radiation plate, which were connected through circulating pipes with a control valve and a water pump. In the cold climate of Xiangtan, experiments and simulations on the solar energy utilization efficiency of the wall were carried out. The results show 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·m2). 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. Increasing the area of thermal radiation plate is beneficial to improving the solar thermal utilization efficiency.