Transcript Heat pump

Heat pump
functioning
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Capacitor
expansion valve
evaporator
compressor
Heat pumps are powered by different physical principles, but are classified according
to their application (transmission of heat, heat source, heat sink or freezer machine).
Efficiency
When comparing the performance of heat pumps, it is best to
avoid the word "efficiency" which has a very specific
thermodynamic definition. The term coefficient of
performance (COP) is used to describe the ratio of useful heat
movement to work input. Most vapor-compression heat
pumps utilize electrically powered motors for their work
input. However, in most vehicle applications, shaft work, via
their internal combustion engines, provide the needed work.
When used for heating a building on a mild day of say 10 °C,
a typical air-source heat pump has a COP of 3 to 4, whereas a
typical electric resistance heater has a COP of 1.0. That is, one
joule of electrical energy will cause a resistance heater to
produce one joule of useful heat, while under ideal
conditions, one joule of electrical energy can cause a heat
pump to move much more than one joule of heat from a
cooler place to a warmer place.
When used for heating a
building on a mild day of say
10 °C, a typical air-source
heat pump has a COP of 3
to 4, whereas a typical
electric resistance heater
has a COP of 1.0. That is,
one joule of electrical energy
will cause a resistance
heater to produce one joule
of useful heat, while under
ideal conditions, one joule of
electrical energy can cause
a heat pump to move much
more than one joule of heat
from a cooler place to a
warmer place
Geothermal heat pump for air conditioning
The geothermal heat pump
uses the ground or water that
is found in the soil as a source
or sink of heat. The transport
of thermal energy is effected
by the same water or using a
liquid anti-freeze, except in
direct expansion heat pumps,
which uses a refrigerant that
circulates in the heat exchanger
placed in the ground.
Unlike air heat pumps, geothermal
cooling also can operate in passive
mode: they extract heat from the building
into the system by pumping cold water or
antifreeze liquid, without the action of the
heat pump itself.
The pipe system that runs through the
land can be opened or closed. In the
open system we extract water from the
underground aquifer, the port is up to the
heat exchanger and then is discharged
into a watercourse, back into the same
aquifer or basin in a purpose-built (and
which allows the rifiltrazione towards the
ground). In the closed system the heat is
intercepted by land through a continuous
buried pipe with an internal coolant (for
pump units) or antifreeze stored at low
temperature and pressure.