Apparatus and method of purging gas turbine exhaust trough to reduce hot flow leakage
AssigneeGeneral Electric Company
InventorsVeerraju Chennoju, Debabrata Mukhopadhyay
Life of this patent
Estimating the term…
Abstract
A purge box, which is added to an expansion joint between an exhaust diffuser and an aft diffuser, can include a cover plate and a T-fairing radially adjacent the cover plate. An inner fairing of T-fairing can be an extension of a duct of the exhaust diffuser and can be attached to a flex seal of the joint. A leg of the T-fairing extends radially outward toward a cover projection extending from a rear of the cover plate. A purge box flow path can have at least one seal therein to reduce flow while accommodating radial and/or axial movement of the duct, the cover plate, and/or the T-fairing to improve operational efficiency of the turbine and safety of those nearby.
Claims20
A purge box for a turbomachine including an exhaust diffuser, an aft diffuser, and an expansion joint including a drain trough therebetween, the purge box including:
- a cover plate attached to a housing of the turbomachine, a portion of the housing acting as a wall of the purge box;
- a flex seal attached to the expansion joint, the flex seal acting as a rear cover of the purge box;
- an inner fairing adjacent an inner periphery of the cover plate with a gap between the inner periphery of the cover plate and the inner fairing;
- a purge box flow path defined by at least the cover plate and the inner fairing from an interior of the purge box to the gap, the gap being adjacent the exhaust diffuser;
- at least one seal in the purge box flow path;
- and
- an inlet through the cover plate and in fluid communication with a source of purging fluid having a pressure selected to induce a pressure in the purge box that is higher than a pressure within the drain trough.
An apparatus for a turbomachine exhaust system, the exhaust system comprising an exhaust diffuser, an aft diffuser, and an expansion joint including a drain trough therebetween, the apparatus comprising:
- a cover plate extending radially from a housing of the turbomachine;
- a T-fairing including an inner fairing adjacent an inner periphery of the cover plate with a gap therebetween, the inner fairing extending substantially parallel to a rotational axis of the turbomachine, the T-fairing further including a leg extending radially outward from the inner fairing adjacent and rearward of the cover plate;
- a rear cover connected to the inner fairing and the housing of the turbomachine;
- a purge box including at least the cover plate, the T-fairing, the rear cover, and the housing of the turbomachine, the T-fairing defining with the inner fairing and the cover plate a purge box flow path from an interior of the purge box, between the cover plate and the leg, and through the gap between the inner periphery of the cover plate and the inner fairing;
- at least one seal in the purge box flow path;
- and
- a purge inlet extending through the cover plate and connected to a source of purging fluid, the purging fluid at a pressure selected to induce a pressure in the purge box that is higher than an operational pressure within the drain trough.
Dependencies are inferred from the claim text.