RANKINE CYCLE HEAT RECOVERY METHODS AND DEVICES

摘要

An integrated expansion turbine/electrical generator assembly (collectively referred to as a "turbo-generator") suitable for use in waste heat recovery and similar applications. The turbo-generator uses a common shaft mounting a one or more stage expansion turbine and a homopolar electrical generator. Magnetic levitating axial and thrust bearings are used to hold the common shaft in its proper position with a fixed housing. The magnetic bearings minimize frictional losses, allowing the common shaft to spin at a very high rotational velocity. Sensor rings continually monitor the common shaft's position. This information is used by control electronics to regulate the magnetic bearings in order to hold the rotating shaft's position. Electrical energy is extracted from the rotating shaft in the form of a direct current. Preferably integrated power-switching electronics are used to generate single or three-phase AC power, which can be phase-matched to an existing power grid or other application.