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Status
Electronic Resource
Call number
Publication
5105 146 DOE JPL 1060 92; Report; September 1985.
Language
Library's review
ABSTRACT:
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
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
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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°c (7S0°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. Show Less