Trane CVGF manual Mechanical Specifications, Compressor, Drive Train, Motor, Lubrication System

Mechanical Specifications

Trane CVGF packaged centrifugal water chillers using HFC-134a refrigerant consist of a hermetic two-stage, gear-drive centrifugal compressor, evaporator, condenser, interstage economizer, unit- mounted microprocessor based control panel, and compressor motor starter. The chiller is entire factory assembled.

Compressor

Two-stage centrifugal compressor with high-strength aluminum alloy, fully shrouded impellers. The impellers are tested at 25 percent over-design operating speed. The rotating assembly is dynamically balanced for vibration of less than 5.1 mm/s (0.2 ips peak velocities) at nominal operating speeds. The control system affords and admitted 100 - 20 percent capacity modulation by electrically actuated guide vanes upstream of each impeller.

Drive Train

The drive train consists of helical bull and pinion gears. Gear tooth surfaces are case hardened and precision ground. The one-piece impeller shaft is supported by hydrodynamic thrust and radial bearings.

Motor

The motor is a hermetic, liquid-refrigerant cooled, two-pole, low-slip, squirrel-cage induction motor. A radial hydrodynamic bearing and duplex angular contact ball bearings support the rotor assembly. Winding-embedded sensors provide positive thermal protection.

Lubrication System

The lubrication system consists of an internal oil sump with heaters, positive displacement oil pump, brazed plate condenser-cooled oil cooler, and oil distillation/return line.

Economizer/Orifice

The economizer consists of a carbon steel shell with internal components designed to prevent liquid carryover to the compressor. Liquid refrigerant is admitted through a single calibrated orifi ce (no moving parts) which maintains a pressure differential between condenser and economizer.

Evaporator

The evaporator is designed, tested and stamped in accordance with ASME Boiler and Pressure Vessel Code or PED (European Code) for refrigerant side working pressure of 15.2 bars (220psig). It consists of a carbon steel shell with steel tube sheets welded to eachend. Intermediate tube support sheets positioned along the shell axis prevent relative tube motion. Individually-replaceable externally-finned and internally-grooved 19 mm (¾ in.) and 25.4 mm (1.0 in.) nominal diameter seamless copper tubes are mechanically expanded into tube sheets.

Two- or three- pass water boxes rated at 10.5 bar (150 psi) is standard. Grooved pipe connections are standard; fl anged connections are optionally available. The waterside is hydrostatically tested at ASME 1.5 times, PED 1.43 times, GB 1.25 times maximum working pressure.

Liquid refrigerant is admitted to the evaporator through a single calibrated orifi ce (no moving parts) which maintains a pressure differential between the economizer and the evaporator.

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