Fuction Heat Pump System - Electrolux EDR 2000 Service Manual

4.1 The principle of operation of the heat pump in the drier circuit
The circuit of the heat pump of the clothes dryer comprises evaporation, compression, condensation, and expansion of
the cooling agent R134a (filling quantity 260g).
This is initially situated in the evaporator (3) in the liquid phase, with the temperature of the moist air exiting from the drum
(1) being higher than the boiling point of the cooling agent. This causes heat to be transferred from the heat source to the
cooling agent, which in turn causes this to receive sufficient energy to evaporate.
This cooling causes the moisture held in the air to condense and to run into the collection dish (7) to be pumped off into
the condensed water tank (9).
The compressor (2) continuously sucks in the cooling agent vapour, which is compressed by a multiple and at the same
time heated. The compressor discharges the heat in the liquefier (4). This in turn heats the air sucked in by the fan (6) and
the now dry air which is readmitted through the drum and takes up moisture.
The cooling agent becomes liquid again and discharges sufficient pressure and temperature through the capillary tube (5)
such that heat can again be taken up in the evaporator (3) from the moist air coming from the drum (1).
This sequence is now repeated continuously in a closed circuit.
If there is water condensation in the collection dish (7), the microswitch triggers, activating the condensate pump (8), which
leads the water to the container (9). When this becomes full, the overflowing water is taken up by the tank of the container
and led back into the collection dish (7)
through a hose (not shown in the dia-
gram). This causes the floater to rise and
to reactivate the microswitch.
The electronic controi system detects
the closure of the microswitch, cuts off
the power to the appliance and
switches on a LED warning the user
that the canister is full.
The tank capacity is about 4 lt., which
is sufficient for one drying cycle
1 Drum
2 Compressor
3 Evaporator
4 Liquefier
5 Capillary tube
6 Fan
7 Collection chamber and floating switch
8 Condensate pump
9 Container
06.2005 R.Kurzke
1
5
3
2
- 7 -
9
6
4
7
599 522 797 EN
8