Application of Gas Bearings to Closed-System Brayton-Cycle Turbomachinery—Recent Accomplishments and Potential Problem Areas

Abstract

Several development programs to demonstrate application of gas-lubricated bearings to gas turbine machinery are presently under way. This paper presents design and initial test data for a 24,000 rpm, 1300 F (turbine inlet temperature) gas-bearing Brayton-cycle turbocompressor operating in a closed-loop system. The bearing system design for a two-shaft power plant, consisting of a 50,000 rpm, 1490 F turbocompressor and a 12,000 rpm turboalternator, is also described. Test results to date demonstrate that gas lubrication, per se, of gas turbine machinery is definitely feasible. However, considerable data are still needed to prove the practical utility of gas bearings. A brief discussion of the needed investigations is presented.