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3. Heat pump unit working principle
3.1 Heat pump working process
● First, the low pressure and superheated gas in the evaporator is inhaled into the compressor then
becomes the high temperature and high pressure overheated vapour.
● Second, the overheated vapour is exhausted into the condenser and exchange the heat with the water,
then the refrigerant is condensed and becomes the saturated or over cooling high pressure and high
temperature refrigerant liquid. The water is heated up by heat pump when absorbing the heat energy
which released by the refrigerant.
● Third, the refrigerant liquid releases the pressure by passing the expansion valve, then becomes the
low temperature and low pressure liquid.
● Fourth, the refrigerant liquid flows into the evaporator and absorb the energy from the air, then is
vaporized and became the low pressure and overheated vapour. The refrigerant working repeatedly as
described above, then the water which flows through the condenser is heated up constantly, the
temperature rise and can get the hot water.
3.2 Air source heat pump working principle
4 way valve
Water inlet
Water Outlet
Condenser
Gas-liquid
separator
Compressor
Filter
Expansion valve
Filter
Ev
ap
or
ato
r
Fa
n
un
it
Figure 1
Q
c
(Heat energy get) =Q
a
(Compressor consumption) +Q
b
(Heat energy absorbed from ambient environment)
