Combustion cap with integral air diffuser and related method

Abstract

A combustion cap assembly for closing a forward end of a combustion chamber includes a radially inner substantially cylindrical component; a radially outer substantially conical component, extending substantially along an entire length dimension of the radially inner component; and an annular airflow passage therebetween. The invention also provides a method for reducing pressure loss across a combustion liner cap assembly located in a gas turbine combustor, the cap assembly supporting a plurality of premix tubes adapted to receive portions of a like number of nozzles, and wherein air flows in an annular passage radially outwardly of the combustor where it reverses direction to flow through the premix tubes, the method including adding a diffuser to the forward end of the cap assembly, the diffuser configured to increase the cross sectional area of the annular flow passage along an axial length of the cap assembly to thereby cause a reduction in velocity of the air in the annular flow passage and thereby reduce pressure loss as the air reverses direction at a forward end of the combustor.

Dependencies are inferred from the claim text.