Method of combustor cycle airflow adjustment

摘要

A method of combustor cycle air flow adjustment for a gas turbine engine according to the present invention solves the problem of a higher flame temperature in the combustor, thereby affecting the emission levels when a heat-recuperated air flow cycle is used to increase the compressed air temperature. In low emission combustors this impact is severe because emission levels are significantly dependent on the primary combustion zone flame temperature. The method of the present invention includes a step of changing a geometry of an air flow passage and thereby changing distribution of a total air mass flow between an air mass flow for combustion and an air mass flow for cooling in order to ensure that flame temperature in a primary combustion zone of a combustor are maintained substantially the same whether the gas turbine engine is manufactured to operate as a simple air flow cycle engine or as a heat-recuperated air flow cycle engine. In an embodiment of the present invention, the changing of the geometry of the air flow passage by changing the number and size of perforations in an impingement cooling skin so that with minimal changes the impingement cooling skin serves duel purposes both as a cooling device for cooling the combustor wall and as a valve means for combustor cycle air flow adjustment, which makes the method simple and economical.