Preliminary Analysis of a Solar Heat Pump System with Seasonal Storage

Artikel i vetenskaplig tidskrift, 2006

For higher solar fraction and suitability for both heating and cooling, a solar heat pump system with seasonal storage was studied in this paper. The system scheme and control strategy of a solar heat pump system with seasonal storage for heating and cooling were set up, which is responsible for the space heating and cooling and domestic hot water for a residential block. Through hourly simulation, the performance and the economics of such systems were analyzed, for the different tank volumes, operating modes and weather conditions. The results show that 1) for most areas of China, the solar systems with seasonal storage can save energy; 2) for areas with cold winter and hot summer, it is suitable to store heat from summer to winter and store cold energy from winter to summer, but for chilly areas, it is suitable to only store heat from summer to winter; 3) when the ratio of volume of seasonal storage tank to collector areas is 2~3, the system performance is optimal and the payback period is shortest for most areas of north China; and 4) if cooling storage is needed, the seasonal storage coupled with short-term storage may raise the solar fraction largely.