18 May 2017

P.2.7.17 Analysis of the Influence of Borehole Depth on Energy Efficiency and Cost of Ground Source Heat Pump System

Ground source heat pump system has been widely used for its clean and efficient in China. The thermal properties of soil have great influence on the heat transfer effect of borehole exchanger. The borehole depth under different geological conditions have a significant impact on the energy efficiency of the ground source heat pump system and the cost of the project. A project was simulated as an example in this paper. The energy efficiency and the cost are calculated in different borehole depth but same load demands. The result shows that, the deeper the borehole is, the more energy efficiency the GSHP system can get in the project. Two typical geological conditions are selected in this paper. In the first geological condition, increasing the drilling depth is an efficient method to improve the energy efficiency of GSHP system, the borehole depth has little influence on the cost. In the second geological condition, shorter borehole exchanger can get more benefits because the drilling depth has a significant impact on the cost.