24 June 2014

Experimental Research on Direct Expansion Ground Source Heat Pump System

Vertical closed-loop ground source heat pump systems (GSHP) have been
installed widely in Korea since it can extract moderate temperature level of geothermal heat in a small area. As a ground heat exchanger, a vertical closed-loop type with brine circulation
is mostly preferred since it is simple and less harmful to ground environment. However, it requires a secondary heat exchange loop between the refrigerant in a heat pump and the
brine. By adding a geothermal heat exchanger in the secondary heat exchange loop, circulation pumps should be attached and the temperature difference between refrigerant and ground is increased, which are important parts of performance degradation. In this
paper, performances of direct expansion (DX) geothermal heat pump were evaluated as an alternative of classical indirect geothermal heat pump.