Product data

23XL Refrigeration Cycle
The compressor continuously draws
refrigerant vapor from the cooler at a
rate determined by the position of
the capacity control slide valve. This
compressor suction reduces the
pressure in the cooler and causes the
remaining refrigerant to boil vigor-
ously at a low temperature (typically
38 to 42 F [3 to 6 C]).
The energy required for boiling is
obtained as heat from the water (or
brine) flowing through the cooler
tubes. With heat removed, the chilled
water (brine) can then be used for
air conditioning or for process
cooling.
After removing heat from the water
(brine), the refrigerant vapor passes
through the compressor. Compression
adds more energy to the refrigerant,
raising its temperature upon discharge
(typically 75 to 95 F [24 to 35 C]) to
a level above that of the water flowing
through the condenser tubes. This
relatively cool condensing water
removes some of the heat from the
vapor, causing it to condense into
a liquid.
The liquid refrigerant passes
through orifices into the FLASC
(FLAsh SubCooler) chamber. Since
the FLASC chamber is at a lower
pressure, part of the liquid refrigerant
flashes to vapor, thereby cooling the
remaining liquid. The FLASC vapor is
recondensed on the tubes which
carry the entering condenser water.
The liquid then passes through a float-
type metering device before return-
ing to the cooler. This float device
maintains a liquid seal to eliminate
inefficient vapor bypass from the
FLASC chamber to the cooler.
On certain models, an economizer
is installed between the cooler and
condenser. With these models, the
float valve meters liquid refrigerant
into the economizer instead of the
cooler. Pressure in this chamber is
intermediate between condenser and
cooler pressures. At this lower
pressure, some of the liquid refriger-
ant flashes to vapor, cooling the
remaining refrigerant. The vapor re-
turns directly to the compressor where
it mixes with vapor from the cooler
at an intermediate point of compres-
sion. This provides an increase in
the mass flow of refrigerant, resulting
in an increase in capacity. The cooled
liquid refrigerant in the economizer
is metered through a float-type meter-
ing device into the cooler. Because
pressure in the cooler is lower than
the economizer pressure, some of the
liquid flashes and cools the remain-
der to evaporator (cooler) temperature.
During both the economized and
non-economized cycles, liquid refriger-
ant returns to the cooler to replenish
the refrigerant leaving as a result of
compressor suction. The cycle is now
complete.
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