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FORM 160.52-O1
5
YORK INTERNATIONAL
7619A(D)
DETAIL A
COMPRESSOR PREROTATION VANES
FIG. 2
REFRIGERANT FLOW-THRU CHILLER
PREROTATION VANES
(See Detail A)
SUCTION
COOLER
ELIMINATOR
OIL COOLER
LD00924
FLOW CONTROL
ORIFICE
SUB-COOLER
CONDENSER
DISCHARGE
BAFFLE
DISCHARGE
COMPRESSOR
full load design conditions. However, most systems will
be called upon to deliver full load capacity for only a
relatively small part of the time the unit is in operation.
CAPACITY CONTROL
The major components of a chiller are selected for full
load capacities, therefore capacity must be controlled
to maintain a constant chilled liquid temperature leav-
ing the cooler. Prerotation vanes (PRV), located at the
entrance to the compressor impeller, compensate for
variation in load (See Fig. 2. Detail A).
The position of these vanes is automatically controlled
through a lever arm attached to an electric motor lo-
cated outside the compressor housing. The automatic
adjustment of the vane position in effect provides the
performance of many different compressors to match
various load conditions from full load with vanes wide
open to minimum load with vanes completely closed.