Patent ID: 8035261
Filing Date: 2011-10-11
Classification: H02K

Abstract:
1. A method to cool a stator and a rotor with a salient pole winding in a bulb turbine generator comprising: circulating a gaseous cooling medium through the bulb turbine generator using at least one fan driven externally of the bulb turbine generator; extracting the gaseous cooling medium from the bulb turbine generator by the fan wherein the gaseous cooling medium is warmed by the bulb turbine generator; conveying the warmed gaseous cooling medium using the fan to a cooling device to cool the gaseous cooling medium; conveying the cooled gaseous cooling medium from the cooling device through a passage between the stator and a casing surrounding the generator, wherein water flowing over an outer surface of the casing cools the casing and the cooled further cools the cooled gaseous cooling medium flowing through the passage; conveying the cooled gaseous cooling medium to the stator via a feed channel between the cooling device and the bulb turbine generator; passing the cooled gaseous cooling medium radially inward through radial stator gaps in a stator core of the stator; after passing through the radial stator gaps, a first portion of the cooling gas flows axially through an air gap between the stator and rotor and a second portion of the cooling gas enters pole gaps and flows axially through the pole gaps, and the fan drawing the cooling gas flows axially out of the air gap and axially out of the pole gaps.