Danfoss TG230 Series, Installation Manual

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Page 19 of 108
M-AP-001-EN Rev. N
Functional Description
Figure 3-1 - Compressor
Fluid Path TG230 / TT300
3 Functional Description
3.1 Main Fluid Path
Compressor operation begins with a call for cooling from a chiller controller. The compressor
controller then begins compressor ramp-up.
The following paragraphs describe the flow of refrigerant from the intake to the discharge
port of the compressor (see Figure 3-1 and Figure 3-2).
The refrigerant enters the suction side of the compressor as a low-pressure, low-
temperature, super-heated gas. The refrigerant gas passes through a set of adjustable Inlet
Guide Vanes (IGVs) that are used to control the compressor capacity at low-load conditions.
The first compression element the gas encounters is the first-stage impeller. The centrifugal
force produced by the rotating impeller results in an increase in both gas velocity and
pressure. The high-velocity gas discharging from the impeller is directed to the second-
stage impeller through de-swirl vanes. The gas is further compressed by the second-stage
impeller and then discharged through a volute via a diffuser (a volute is a curved funnel
increasing in area to the discharge port. As the area of the cross-section increases, the volute
reduces the speed of the gas and increases its pressure). From there, the high-pressure/
high-temperature gas exits the compressor at the discharge port.
Discharge Port
Volute
Assembly
1st Stage
Impeller
Low - Pressure / Low -
Temperature Gas
Inlet Guide Vanes
(IGV)
Vaned
Diffuser
2nd Stage Impeller
High - Pressure / High -
Temperature Gas