Solar heating is a clean and promising way for space heating, however, the demand for low-temperature heat in non-heating seasons is very little, which also cause the extremely high cost of space heating. A flexible solar heating system is proposed in this paper, besides supplying heat in winter, it can upgrade low-temperature heat to process steam through a heat pump in nonheating seasons. The thermodynamic performance of the proposed system using in a textile mill is investigated. The system consists of a solar collector with an area of 120 m2 , a storage tank with a capacity of 50 kW and an ammonia compression-absorption heat pump with a capacity of 30 kW. The yearly natural gas saving and CO2 emission reduction of the proposed system reaches 4957.64 m3 and 5941.3 kg in total. The economic analysis turns out the investment would be recovered in 7.87 years, which is 54.13% less than that of the solar space heating system without an HP (14.17 years). Furthermore, the influences of the solar collector area, the capacity of the storage tank and heat pump on the proposed system are carried out.
Keywords Solar energy, Space heating, Heat pump, Steam production