Turbomachinery Laboratory, Texas A&M Engineering Experiment Station
Abstract
LecturesThe giant Groningen onshore gas field in the Northeastern
Netherlands started production in 1963. About 35 years later,
the decreasing reservoir pressure required a first stage of compression
to provide sufficient capacity at the required 65 bar
(940 psi) grid pressure. Now, a first pilot plant for a second
stage of compression is installed in the accelerated cluster
Schaapbulten (SCB) and started production end of 2013.
The novel compression string installed consists of a 23-
MW synchronous, high-speed motor in a double-end-drive configuration,
driving two gearless driven 7- and 8-stage compressors.
The approximate 16m (52ft) long train, with about 14mm
(0,55inch) axial thermal elongation, is supported by six radial
active magnetic bearings (AMBs) and two axial AMBs at the
train’s non-driven ends.
This contribution deals with the axial, radial and torsional
rotordynamics of the AMB-supported string focusing on the
two compressors, as well as with string design aspects and latest
field / operational experiences. The design aspects touch
points like the trade-off in the coupling selection process and
resonance frequency optimizations. Field experiences concerning
experimental torsional string analysis and run-out effects in
combination with the closed loop AMB controller design are
presented. Derived and presented improvements hav
