The design method of U-bend geothermal heat exchanger of DX-GCHP in cooling model

摘要

The design method of the U-bend vertical geothermal heat exchanger (GHE) of the direct-expansion ground-source heat pump (DX-GSHP) system in the cooling mode is developed in this paper. The impact of the gravity of the two-phase fluid was taking into consideration, and the pressure-enthalpy diagram of the DX-GSHP system is developed. The determination of the copper pipe diameter and the pipe spacing are presented in this paper. Furthermore, the recommended diameter, spacing and borehole length were given. The method developed in this paper can be used as guidance for the design of GHE for DX-GSHP systems.