Nowadays industrial processes are going toward high power density solutions.
This can be read as a general increase in pressure (more than 200 barA) and fluid density indicating Turbo Expander (TEX) as a worthwhile solution to boost main process compressors and increasing process efficiency.
On the other hand, inlet high pressure and high density fluids could lead to strong pressure pulsations on the impeller with consequences on the rotordynamic behavior, rotor stability and bearing integrity.
For this purpose, a full annulus unsteady CFD analysis of the flow path through the inlet plenum, nozzles and impeller has been performed and analyzed in terms of resulting force FFT on the impeller.
The force signal is used as an input of the rotor model supported by Active magnetic bearings (AMB), including their control system and transfer function.
The aim of the study is the investigation of the influence of high density gas in TEX applications, coupling the results of unsteady CFD analysis with the dynamic response of the mechanical system.
The control system parameters of magnetic bearings are included into the analysis and a sensitivity to different inlet nozzles numbers and inlet pressure levels is performed verifying the feasibility of the rotor.