Bearing development program for a 25-kWe solar-powered organic Rankine-cycle engine

Technical Report · Sun Sep 15 04:00:00 EDT 1985

DOI:https://doi.org/10.2172/6432713· OSTI ID:6432713

Nesmith, B.

This report summarizes the bearing development program for a 25-kWe power conversion subsystem (PCS) consisting of an organic Rankine-cycle engine, permanent magnet alternator (PMA) and rectifier to be used in a 100-kWe point-focusing distributed receiver solar power plant. The engine and alternator were hermetically sealed and used toluene as the working fluid. The turbine, alternator, and feed pump (TAP) were mounted on a single shaft operating at speeds up to 60,000 rev/min. Net thermal-to-electric efficiencies in the range of 21 to 23% were demonstrated at the maximum working fluid temperature of 400/sup 0/C (750/sup 0/F). A chronological summary of the bearing development program is presented. The primary causes of bearing wear problems were traced to a combination of rotordynamic instability and electrodynamic discharge across the bearing surfaces caused by recirculating currents from the PMA. These problems were resolved by implementing an externally supplied, flooded-bearing lubrication system and by electrically insulating all bearings from the TAP housing. This program resulted in the successful development of a stable, high-speed, toluene-lubricated five-pad tilting-pad journal bearing and Rayleigh step thrust bearing system capable of operating at all inclinations between horizontal and vertical.

• Research Organization: Jet Propulsion Lab., Pasadena, CA (USA)
• DOE Contract Number: AI04-80AL13137
• OSTI ID: 6432713
• Report Number(s): DOE/JPL-1060-92; JPL-PUB-85-81p; ON: DE87005430
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140700* -- Solar Thermal Power Systems
BEARINGS
CONCENTRATING COLLECTORS
DESIGN
ENGINES
EQUIPMENT
FLUIDS
HEAT ENGINES
PARABOLIC COLLECTORS
PARABOLIC DISH COLLECTORS
RANKINE CYCLE ENGINES
SOLAR COLLECTORS
SOLAR EQUIPMENT
WORKING FLUIDS