Patent ID: 6615574
Filing Date: 2003-09-09
Classification: F02C

Abstract:
A system for bleeding air from plural ports in a multi-stage compressor to provide cooling and/or sealing air to an associated turbine for optimizing gas turbine performance, comprising:a first casing portion surrounding a lower pressure stage of the compressor, said first casing portion having at least one bleed aperture defined therethrough; a first extraction flow path for conducting bleed air from said first casing portion to the turbine; a second casing portion surrounding a mid pressure stage of the compressor, said second casing portion having at least one bleed aperture defined therethrough; a second extraction flow path for conducting bleed air from said second casing portion to the turbine; a first cross over flow path interconnecting said first extraction flow path and said second extraction flow path for selective cross over flow therebetween; a first control valve provided in said first extraction flow path, upstream of said first cross over path; a second control valve provided in said second extraction flow path, upstream of said first cross over path; a first cross over control valve provided in said first cross over flow path for selectively controlling flow between said first extraction flow path and said second extraction flow path; and an ejector in flow communication with said first cross over flow path and said second extraction flow path, at a junction therebetween, whereby flow through and between said first and second extraction flow paths can be selectively controlled to supply air to the turbine at a proper pressure with an economic mixture of bleed air, so that the lower pressure, first extraction flow path can be communicated to a target portion of the turbine at a higher pressure than said low pressure extraction.