Electrolux R134A, Service Manual

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All refrigerators cool by removing heat
from the cabinet rather than pumping in cool
air. In a conventional refrigerator, liquid re-
frigerant enters the evaporator and vapor-
izes (boils) due to the low pressure, creat-
ing a very cold surface which removes heat
from inside the cabinet. This causes the re-
frigerant to boil (evaporate) into a vapor
state and be drawn into the compressor.
The compressor pressurizes the vapor and
pumps it into the condenser. The hot va-
por in the condenser gives off the heat into
the room. As the vapor cools, it condenses
back into a liquid and returns to the evapo-
rator to start the process over again. The
system continually soaks up the heat inside
the refrigerator and deposits the heat back
into the room.
• The compressor
compressor
compressor compressor compressor of the refrigeration sys-
tem serves two purposes: it ensures
movement of the refrigerant throughout
the system and it increases the pressure
and temperature of the vapor received
from the suction line and pumps the re-
frigerant into the discharge line. The
condenser receives this high tempera-
ture, high pressure refrigerant and al-
lows the heat to be released into the
cooler surroundings. This heat removal
"condenses" the refrigerant vapor into a
liquid.
• The yoder loop yoder loop yoder loop yoder loop yoder loop is the last pass of the
condenser routed around the cabinet of
the freezer to help prevent moisture for-
mation.
• The drier drier drier drier drier is installed at the end of the
condenser or yoder loop to capture
moisture which may be present in the
system.
REFRIGERA REFRIGERA
REFRIGERA REFRIGERA REFRIGERATION SYSTEM
TION SYSTEM
TION SYSTEM TION SYSTEM TION SYSTEM
•
The
capillary tube capillary tube
capillary tube capillary tube capillary tube meters the flow of
refrigerant and creates a pressure drop.
Size and length of the capillary is critical
to the efficiency of the system.
• As the refrigerant leaves the capillary
tube and enters the larger tubing of the
evaporator evaporator
evaporator evaporator
evaporator, the sudden increase in tub-
ing diameter, and the pumping action of
the compressor, form a low pressure
area. The temperature of the refriger-
ant drops rapidly as it changes to a mix-
ture of liquid and vapor. In the process
of passing through the evaporator, the
refrigerant absorbs heat from the stor-
age area and is gradually changed from
a liquid and vapor mixture (saturated
refrigerant) into a vapor.
• The suction line suction line
suction line suction line
suction line returns this low pres-
sure vapor from the evaporator back to
the compressor, and the cycle starts
again.
• Part of the capillary tube is soldered to
the suction line which forms a heat
heat
heat heat heat
exchanger exchanger exchanger exchanger exchanger..... Heat from the capillary tube
is thus transferred to the suction line to
superheat the refrigerant there and at the
same time this further cools the liquid
in the capillary tube. This cools the re-
frigerant before it enters the evaporator
and also heats the refrigerant before it
enters the compressor to ensure a va-
por state.