On Space Heating Application Of Solar Low-Temperature Water Heating System In Lhasa

In this paper, the feasibility of solar low-temperature water heating system in Lhasa was studied, which is based on the investigation of present situation of energy supply, space-heating in winter and solar energy resources in this area. The work involves three parts: the energy consumption of the building, the performance of the system and the indoor thermal comfortability.A solar low-temperature water heating system is designed and described. At first, dynamics heat load of this civil building is analyzed. It is found that in different month the heat load is quite different. Also, the factors which have influences on the building's unit heat load is analyzed. The solar low-temperature heating system was designed according to the heat requirement of the building. One kind of evacuated tube solar collectors with indirect heat exchanger is used to collect solar energy, and floor radiant heating is adopted in combination with periodic running heating method. The floor temperature and air temperature of the heating room and the non-heating room are measured. The result of experiment shows that the efficiency of the system is 30.8%. It is found that the average air temperature of floor radiant heating room is 15.9℃, which is 6.5℃higher than that of non-heating room. The calculated mean radiant temperature of floor heating room is 24.2℃, and the perceived room temperature is 3.3℃higher than the indoor air temperature. The experiment results show that the solar energy received in a day of this system can meet the heat requirement of the building.Compared with other heating method existed in this area, this system consumes less electricity and relative small operation expenditure, it's a potential heating technology which is suitable for Tibet area.