Groundwater

The effects of groundwater direction on performance of geothermal heat pump systems were analyzed using a 3-D finite difference method with rectangular meshes. Each borehole was approximated by a square column with the actual circular borehole section circumscribing the approximated square section. The fluid temperatures inside each borehole were calculated by discretizing borehole vertically into different segments.

The groundwater heat pump (GWHP) system is an open-loop system that draws water from a well orsurface water, passes it through a heat exchanger and discharges the water into an injection well ornearby river. By utilizing the relatively stable temperature of groundwater, this system can achieve ahigher coefficient of performance and offers a more energy-saving solution than the conventionalair-source heat pump (ASHP) system. On the other hand, its performance significantly depends on thecharacteristics of the groundwater and the underground thermal properties.