In: Physics
Explain the thermodynamic principle of a geothermal heat pump.
A geothermal heat pump or ground source heat pump (GSHP) is a
central heating and/or cooling system that transfers heat to or
from ground. Geothermal heat pumps basically have the same working
principle like air conditioners or refrigerators, by using the
transfer of heat. Geothermal heat pumps can transfer heat from a
cool space to a warm space, against the natural direction of flow,
or they can enhance the natural flow of heat from a warm area to a
cooler space, which depends whether they are used for heating
(during the winter) or for the cooling purposes (during the
summer). A ground source heat pump absorbs heat from the ground –
by circulating water though piping in the ground – and transfers
the heat into the building by circulating hot water though
radiators, or underfloor piping circuits. In a heat pump, the
refrigerant is evaporated by the ground heat, the resulting
gas is compressed and thus heated, and then the hot gas supplies
its heat to the
heating system. The measure for this efficiency is the COP for an
electric compression heat pump defines as COP = (useful
heat)/(electric power input)