Compact Closed Cycle Brayton System Feasibility Study.

This report presents the feasibility of a closed Brayton cycle power conversion system for compact light weight naval propulsion plants. Reference case requirements have been established, including a unit output of 70,000 horsepower, turbine inlet gas temperature of 1700 F, and use of helium as the working fluid. Critical components such as bearings and compact heat exchangers have been evaluated and shown to have more than one suitable design solution. The cross-counterflow tubular type of heat exchanger was selected for the design concept precooler and intercooler. The tube and shell type of heat exchanger was selected for the recuperator. Gas bearings were selected for inclusion in the design concept. Preliminary designs of the most critical portion of the turbomachinery rotor, the first stage turbine, have been derived. Material tests have provided data which are important to this study and also have provided significant extensions to the data available to the materials community. An initial design concept has been defined for an integrated power conversion system which has the necessary characteristics and is appropriate for the most stringent requirements associated with the various energy sources, fossil or nuclear, which the Navy could desire to use.