Abstract：

Introduces the concept of accumulated load ratio to quantitatively describe the imbalance between heating and cooling loads of the ground heat exchanger (GHE). Holds that the design length of boreholes in the GHE relies not only on the loads themselves but also on the available temperature differences in cooling and heating conditions respectively. Therefore presents the conception of cooling/heating-dominated applications. With some calculation examples, simulates four typical cases with different load characteristics to study the variations in temperatures of the ground and circulating fluids over a long period of operation, and to analyse the impact of the space between boreholes on GHE performances under different load characteristics.