Operation performance of central solar heating system with seasonal storage water tank in Harbin

This paper presented a preliminary research on the central solar heating system with seasonal storage (CSHSSS) used in cold climate in China. A mathematical model of the solar energy seasonal storage water tank used in the central solar heating system was firstly developed based on energy conservation. This was followed by the simulation of the CSHSSS used in a two-floor villa in Harbin, and the analysis of the impacts on storage water temperature of tank volume, solar collector area, tank burial depth, insulation thickness around the tank, etc. The results show there is a relatively economical tank volume to optimize the system efficiency, which decreases with increasing tank volume at the constant collector area, and increases with increasing collector area at the constant tank volume. Furthermore, the insulation thickness has obvious effect on avoiding heat loss, while the tank burial depth doesn't. In addition, the relationship between the solar collector efficiency and storage water temperature was also obtained, it decreases quickly with increasing storing water temperature, and then increases slowly after starting space heating system. These may be helpful for relevant design and optimization in cold climates in China and all over the world.