Abstract: A compact axial turbine configured to operate with high density working fluid is described. The turbine comprises an axial majority cantilevered turbomachinery shaft. Rotor assemblies and nozzle spacers communicate torque through turbine shaft splines, allowing them to be slid off the shaft for quick replacement in the field. The compact axial turbine houses turbomachinery within a separable inner casing encircled by a cartridge sleeve, thereby forming a cartridge which can itself be removed as a single component.

Abstract: Provided herein is a power generation system and method for transforming thermal energy, such as waste heat, into mechanical energy and/or electrical energy. The system employs features designed to accelerate start times, reduce size, lower cost, and be more environmentally friendly. Tire system may include multiple compressors on separate pinion shafts with multiple expanders, a temperature valve upstream of compressors with a mass management system downstream, an intercooler between compressors, and a cascade exchanger. In one embodiment, the system is configured to drive a synchronous generator, with the separate pinion shafts rotating at two separate, but constant, speeds.