초록 ▼

A method of operating a gas turbine having inner and outer shells, with the inner shell being radially movable relative to rotor bucket tip passage in the inner shell for flowing a thermal medium. A pair of passage portions are formed in each of the aft and forward inner shell sections with axially

A method of operating a gas turbine having inner and outer shells, with the inner shell being radially movable relative to rotor bucket tip passage in the inner shell for flowing a thermal medium. A pair of passage portions are formed in each of the aft and forward inner shell sections with axially communicating passageways between the passage portions. A thermal medium, preferably from an off-turbine site, is provided for flow through the second-stage aft inner shell section, along axial passageways along the mid-line of the inner shell to a first passage portion of the forward inner shell section. Cross-over paths flow the thermal medium from the first passage portions to second circumferentially extending passage portions of the forward inner shell section, in turn, in communication with axial passageways extending from the forward section to the aft section. A second pair of passage portions flow the thermal medium to an outlet in the aft section. By controlling the temperature of the thermal medium for flow through the aft and forward sections of the inner shell, the clearance between the shrouds and the tips of the buckets for at least the first and second stages of the turbine is controllably adjusted.

대표청구항 ▼

1. A method of operating a turbine having a rotor including axially spaced buckets carried thereby forming parts of turbine stages, an outer containment shell, an inner shell about the rotor including nozzles carried thereby forming other parts of said turbine stages and shrouds about the respective

1. A method of operating a turbine having a rotor including axially spaced buckets carried thereby forming parts of turbine stages, an outer containment shell, an inner shell about the rotor including nozzles carried thereby forming other parts of said turbine stages and shrouds about the respective tips of said buckets of said stages, and a passage formed in said inner shell for flow of a thermal medium to control thermal movement of said inner shell, comprising the steps of:flowing the thermal medium serially (i) through passage portions of the inner shell at a first axial location corresponding in part to an axial location of a second stage of said turbine, (ii) forwardly along said inner shell from said first axial location to passage portions of said inner shell at a second location corresponding in part to an axial location of a first stage of the turbine and (iii) rearwardly along said inner shell from said second axial location to passage portions of said inner shell at said first axial locations to control the thermal radial expansion and contraction of said inner shell and the clearance between the tips of the buckets and shrouds of each said first and second stages.