CROSS-REFERENCE TO RELATED APPLICATIONS

Not applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

TECHNICAL FIELD

This present disclosure relates generally to a system for improving airflow supply and distribution to a gas turbine combustor. More specifically, embodiments of the present disclosure relate to a reconfigured air flow inlet region between a transition duct and a flow sleeve of the gas turbine combustor.

BACKGROUND OF THE DISCLOSURE

A gas turbine engine typically comprises a multi-stage compressor coupled to a multi-stage turbine via an axial shaft. Air enters the gas turbine engine through the compressor where its temperature and pressure increase as it passes through subsequent stages of the compressor. The compressed air is then directed to one or more combustors where it mixes with a fuel source to create a combustible mixture. This mixture is ignited in the one or more combustors to create a flow of hot combustion gases. These gases are directed into the turbine causing the turbine to rotate, thereby driving the compressor. The output of the gas turbine engine can be mechanical thrust via exhaust from the turbine or shaft power from the rotation of an axial shaft, where the axial shaft can drive a generator to produce electricity.

In a typical industrial gas turbine engine, the combustor section comprises a plurality of can-annular combustors. In this arrangement, a plurality of individual combustors is arranged about the axis of the gas turbine engine. Each of the combustors typically comprises a combustion liner positioned within a flow sleeve and one or more fuel nozzles located at an inlet of the combustion liner. Compressed air passes between the flow sleeve and the combustion liner and along an exterior surface of the combustion liner prior to being mixed with fuel in the combustion liner. By directing compressed air over the combustion liner, the air cools the combustion liner and is pre-heated prior to combustion, resulting in a more efficient combustion process. The air from the engine compressor can also be used to cool a transition duct, which, as one skilled in the art understands, is used to direct hot combustion gases from the combustion liner to the turbine inlet.

In prior art combustion systems, a portion of the compressed air was injected into the passage between the combustion liner and flow sleeve through a series of injection ports in the flow sleeve. This prior art configuration is shown inFIG. 1and includes a flow sleeve100having a plurality of openings102and injection ports or tubes104. Positioned within the flow sleeve100is a combustion liner106which is coupled to a transition duct108. The transition duct108includes an outer cooling sleeve110. Air from the engine compressor enters a channel112formed between the transition duct108and the outer cooling sleeve110and flows along an outer wall of the transition duct108and an outer wall of the combustion liner106, as indicated by the arrows inFIG. 1. The openings102and injection ports104of the flow sleeve100provide jets of cooling air aimed towards the combustion liner106. This arrangement creates a cross flow of cooling air resulting in an adverse interaction between air entering through the openings102and injection ports104and air in the channel112. As such, cooling of an aft end of the combustion liner is not as effective as desired.

BRIEF SUMMARY OF THE DISCLOSURE

The following presents a simplified summary of the disclosure to provide a basic understanding of some aspects thereof. This summary is not an extensive overview of the application. It is not intended to identify critical elements of the disclosure or to delineate the scope of the disclosure. Its sole purpose is to present some concepts of the disclosure in a simplified form as a prelude to the more detailed description that is presented elsewhere herein.

The present disclosure provides systems and methods for improving a flow of cooling air to a gas turbine combustion system, thereby providing a more uniform distribution of cooling air along a combustion liner.

In an embodiment of the disclosure, a transition duct for a gas turbine engine is provided and comprises an inlet ring, a duct body connected to the inlet ring, and an aft frame connected to the duct body. A bellmouth is positioned radially outward of the inlet ring and encompasses the inlet ring. A plurality of struts extends between the bellmouth and the inlet ring, where the struts have a leading edge, an opposing trailing edge, and a thickness. In this configuration, air for combustion in the gas turbine engine passes through the bellmouth, between the plurality of struts and is directed to a combustion system coupled to the transition duct.

In an alternate embodiment of the disclosure, a flow inlet device for a gas turbine combustor is provided. The flow inlet device comprises an inlet ring, a bellmouth positioned radially outward of and encompassing the inlet ring, and a plurality of struts extending between the inlet ring and the bellmouth. The inlet ring and the bellmouth direct air for use in the gas turbine combustor between the plurality of struts.

In yet another embodiment of the disclosure, a method of increasing airflow to a gas turbine combustor is provided. The method provides a transition duct for a gas turbine engine having an inlet ring, a duct body connected to the inlet ring, an aft frame connected to the duct body, a bellmouth positioned radially outward and encompassing the inlet ring, and a plurality of struts positioned between the bellmouth and the inlet ring, where the struts have a leading edge, an opposing trailing edge, and a thickness. A flow sleeve is coupled to the transition duct and a flow of air is directed through the bellmouth, between the plurality of struts, and towards an inlet of the gas turbine combustor.

The present disclosure is aimed at providing an improved way of directing cooling air into and along a gas turbine combustion system including improvements to various combustor hardware, such that overall cooling air distribution is improved.

These and other features of the present disclosure can be best understood from the following description and claims.

