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http://dx.doi.org/10.9725/kts.2022.38.2.33

Rotordynamic Analysis and Operation Test of Turbo Expander with Hydrostatic Bearing  

Lee, Donghyun (Dept. of System Dynamics, Korea Institute of Machinery and Material)
Kim, Byungock (Dept. of System Dynamics, Korea Institute of Machinery and Material)
Jung, Junha (Dept. of System Dynamics, Korea Institute of Machinery and Material)
Lim, Hyungsoo (Dept. of Energy Conversion, Korea Institute of Machinery and Material)
Publication Information
Tribology and Lubricants / v.38, no.2, 2022 , pp. 33-40 More about this Journal
Abstract
In this study, we present rotor dynamic analysis and operation test of a turbo expander for a hydrogen liquefaction plant. The turbo expander consists of a turbine and compressor wheel connected to a shaft supported by two hydrostatic radial and thrust bearings. In rotor dynamic analysis, the shaft is modeled as a rigid body, and the equations of motion for the shaft are solved using the unsteady Reynolds equation. Additionally, the operating test of the turbo expander has been performed in the test rig. Pressurized helium is supplied to the bearings at 8.5 bar. Furthermore, we monitor the shaft vibration and flow rate of the helium supplied to the bearings. The rotor dynamic analysis result shows that there are two critical speeds related with the rigid body mode under 40,000 rpm. At the first critical speed of 36,000 rpm, the vibration at the compressor side is maximum, whereas that of the turbine is maximum at the second critical speed of 40,000 rpm. The predicted maximum shaft vibration is 3 ㎛, whereas sub-synchronous vibration is not presented. The operation test results show that there are two critical speeds under the rated speed, and the measured vibration value agrees well with predicted value. The measured flow rate of the helium supplied to the bearing is 2.0 g/s, which also agrees well with the predicted data.
Keywords
Hydrostatic bearing; Turbo expander; Orifice; Hydrogen liquefaction;
Citations & Related Records
Times Cited By KSCI : 1  (Citation Analysis)
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