CG-PRC002A-EN
31
Mechanical
Especifications
Cooling Components
Trane 20, 25 and 30Tons CGAD Air-
Cooled Liquid Chillers have only one
cooling circuit, and the 40, 50, 60, 70 , 80
and 90 Tons units have two independent
cooling circuits. Each cooling circuit is
supplied with the following components:
- Thermostatic expansion valve;
- Tank valve at condenser outlet, with a
pressure intake point of 1/4" SAE;
- Liquid sightglass with humidity indicator;
- Dryer filter;
Fig. 29 - Expansion
Valve
Fig. 28 - Liquid Sightglass
Compressor Scroll
Compressors Scroll provide more benefits
to the air conditioning system user when
compared to reciprocating compressors.
- They have a 5 to 10% higher efficiency, in
average;
- They do have no valves, being extremely
resistant to slugging;
- They have 64% fewer moving parts;
- Extremely smooth and silent operation,
comparable to a centrifugal compressor;
- Low torque variation, which provides
vibration and noise reduction and increa-
ses motor life.
Fig. 30 - Comparison Scroll x Reciprocal
Fig. 31 - Drier Filter
Filtering Element
Compression Cycle
Figure 28 shows a Scroll compressor in
detail, presenting its main components
and the operational principle, according to
the items below:
A. The refrigerant, in gaseous state , is
suctioned into its interior though the sucti-
on connection.
B. The refrigerant passes through a cavida-
ty between the rotor and the stator, cooling
the motor .
C. The refrigerant speed decreases when it
leaves the motor cavity and the oil is sepa-
rated. The oil returns to the crankcase..
D. The refrigerant goes into the suction
chamber and fills out the compression
scroll.
E. After compression, the refrigerant is
dischraged in the compressor hood throu-
gh a hole in the center of the fixed Scroll.
The hood function is to amortize the refri-
gerant flow, reducing vibrations. Then the
refrigerant leaves the compressor through
the discharge connection.
FIg. 32 - Compressor Scroll
Fixed Scroll
C
Moving
Scroll
A
Suction
E
Discharge
Motor
Check Valve
D
B
Motor
Shaft
Oil Pump
