Ground-Coupled Heat Pumps for Heating-Only and Heating and Cooling Operation

摘要

For heat pump systems the ground acting as an intermediate store can be used as heat source/heat sink for heating-only as well as for heating and cooling operation. By eliminating peaks of the outside air temperature, the ground offers the possibility of improving the efficiency of heat pump systems remarkably. The most interesting applications are so-called low-exergy systems, where "high-temperature" cooling can be achieved by using the ground directly without using a heat pump chiller. However, some important boundary conditions have to be investigated carefully like the properties of the ground, the moisture migration in the ground, the operation hours of heating and cooling operation, and the ratio of heat extraction and recharging of the ground to achieve stable operating conditions over the years, i.e. that no temperature change appears. The energy consumption in the building sector, which is still the largest end-use energy consumer, can be reduced significantly by utilizing the ground in an efficient way.