Page 98 - Compression Machinery for Oil and Gas

Centrifugal Compressors Chapter 3 87

Thrust bearing temperature vs. inlet flow coefficient
150
148
146
Temperature (F) 142
144

140
138
136
Low-speed inboard Outboard
134
Design-Speed inboard Outboard
132
High-Speed inboard Outboard
130
0.030 0.035 0.040 0.045 0.050 0.055 0.060 0.065 0.070 0.075
Inlet flow coefficient
FIG. 3.53 Thrust bearing temperature as a function of operating point.

Axial gap vs. inlet flow coefficient
7.0
Low speed
6.0
Design speed
Averaged axial gap (mi) 4.0
High speed
5.0

3.0

2.0

1.0
0.0
0.030 0.035 0.040 0.045 0.050 0.055 0.060 0.065 0.070 0.075
Inlet flow coefficient
FIG. 3.54 Axial position of the rotor as a function of the operating point.

radial direction, is usually much smaller than the pressure forces. At very high
discharge pressures near choke, when the pressure differential over the impeller
is rather small, the momentum force can become dominant, and create a net
force toward the discharge end of the compressor.