Abstract
In the remote areas of northern China without central heating and gas supply, for users intending to replace coal-boilers, the air-source heat pump system is always questionable due to the contradiction between its heating capacity and user’s heating demand, especially in very cold areas, whose COP and economy is very poor. The accumulator with phase change materials would be a promising one to solve this problem. With the help of TRNSYS software, a heating system coupled with air-source heat pump, accumulator, and water-source heat pump and its operation mode are provided and analyzed based on the heat source renovation demand of a middle school in Tianshui City suburb which has 5560 m2 area to be heated. The average COP simulated during the heating period of the coupled heating system is 2.23. Based on the simulation model and results, the heat source renovation of the middle school in Tianshui City suburb was carried out, its tested and simulated COP over the day was 2 and 2.05, respectively, which also reveals the validity of the numerical method for this problem.