Thermally compliant combustion cap device and system

Abstract

A combustion cap plate is disclosed. The combustion cap plate includes: a plate having a planar surface and configured to be affixed to an assembly connected to a turbine combustion chamber, the plate defining a central axis perpendicular to the planar surface; a plurality of openings through the plate; and a plurality of raised portions formed by the plate. The raised portions each extend away from the planar surface in a direction of the central axis and having a shape conforming to a thermal gradient incident on the plate during a combustion process.

Description

BACKGROUND OF THE INVENTION[0001]The subject matter disclosed herein relates to gas turbines and, more particularly, to combustion cap assemblies used in gas turbines.[0002]Combustion cap assemblies are utilized in gas turbines to deliver fuel and air from fuel nozzles to a combustion chamber in the turbines. Combustion cap assemblies typically include a cap plate through which fuel nozzles deliver fuel and air.[0003]Current cap plates have low cycle and high cycle life limitations. The life limitations are in the form of cracks in the cap plate. Some of the cracking experienced is initiated from low cycle fatigue due to severe thermal gradients caused by proximity to flames in the combustion chamber. Some of the cracking is also due to high cycle fatigue because the relatively low stiffness of the cap plate allows it to be deflected by combustion pressure pulsations.[0004]Some designs attempting to extend the life limitations include thickening the plate to make it have higher life...

AI Technical Summary

Benefits of technology

[0007]Additional features and advantages are realized through the techniques of exemplary embodiments of the invention. Other embodiments and aspects of the invention are described in detail herein and are considered a part of the claimed invention. For a better understanding of the invention with advantages and features thereof, refer to the description and to the drawings.

Problems solved by technology

Current cap plates have low cycle and high cycle life limitations.

The life limitations are in the form of cracks in the cap plate.

Some of the cracking experienced is initiated from low cycle fatigue due to severe thermal gradients caused by proximity to flames in the combustion chamber.

Some of the cracking is also due to high cycle fatigue because the relatively low stiffness of the cap plate allows it to be deflected by combustion pressure pulsations.

This increased thickness makes it harder to manufacture and increases cost.

The increased thickness may also lead to a discontinuity where a thicker plate is attached to a thinner plate.

Devices including such shields require more parts, complexity and cost than systems with a single cap plate.

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