Apparatus for cooling an electrical generator

Claim 2

In a gas-driven turbo-generator set wherein the gaseous working medium is first compressed in a compressor, then heated to impart energy thereto, and then passed through a turbine which is shaft coupled to the compressor and to an electric generator, the improvement for effecting generator cooling which comprises means for conveying a portion of said gaseous working medium following compression in said compressor to said generator for cooling the latter, said geneRator including a closed flow path including fan means for circulating the pressurized gaseous working medium through it and a cooler for removing heat therefrom.

Claim 3

The invention as defined in claim 1 wherein said turbo-generator set operates on an open cycle and wherein air constitutes the gaseous working medium used for generator cooling and for driving the turbine.

Claim 4

The invention as defined in claim 1 wherein said means for conveying a portion of the gaseous working medium pressured in said compressor to said generator includes a pressure regulating valve.

Claim 5

The invention as defined in claim 3 and which further includes means controlling said pressure regulating valve in accordance with the output delivered by said generator such that the pressure of the gaseous working medium changes in the same sense as the generator load.

Claim 6

The invention as defined in claim 1 and which further includes valve controlled means for allowing escape of the cooling gas from said generator when said turbo-generator set is shut down thereby to relieve the pressure within the generator.

Claim 7

The invention as defined in claim 1 wherein said means for conveying a portion of the gaseous working medium pressurized in said compressor to said generator includes a pressure regulating valve controlled in accordance with the output delivered by said generator such that the pressure of the gaseous working medium changes in the same sense as the generator load, and which further includes a return path for the gaseous working medium from said generator to the intake side of said compressor, said return path including a throttle valve which opens only when said turbo-generator set is shut down, and said throttle valve likewise being controlled by the generator output and in the same sense as said pressure regulating valve.

Claim 8

The invention as defined in claim 1 wherein said compressor includes at least two stages interconnected by an interstage cooler, and wherein said means for conveying a portion of said gaseous working medium to said generator includes a pipe line connected to the gas outlet side of said interstage cooler.