Designed and simulation of the ground source heat pump system used in archives

The Ground Source Heat Pump (GSHP) system used in Shanghai Minhang archives is the first archives project using the GSHP system in China. This archives covers with an area of 8000 m², and the peak load in summer is 1000 kW, which in winter is 700 kW. To abate the inference made by difference between the heat emanated to the soil in summer and the heat absorbed from the soil in winter, this project has used the heat recover technique, and the recovering heat quantity is 495 kW with calculating. According to the peak load and the located situation, the underground exchanger of this GSHP system is composed with 280 holes in which there are single U pipes with 80 m deep, and the distance between each hole is 4 m. We divided the 280 holes to 10 sections for the purpose of adjustment when the load is low. Two heat pumps were chosen for this project. Besides satisfying the load in summer and winter, the heat pumps will supply hot water for daily use in the whole years. Because of the specialization of the archives which demands a steady temperature and humidity, the heat pumps have to run all the years, but we can use only one heat pump in low load days like spring and autumn. Based on this project, the paper simulates the GSHP system with the actual condition. The result of simulation shows that it should reasonably increase the deepness of the underground pipes if allowed, and the heat recover technique can alleviate the heat store in soil without influencing the performance of the heat pump.