RICH BURN QUICK QUENCH LEAN BURN COMBUSTOR OF ANNULAR CONFIGURATION WITH VARIABLE CROSS-SECTION PRIMARY REACTION REGION

摘要

An annular configuration of a combustion device for micro gas turbine engine that contains an annulus liner and casing, having circumferentially arranged swirlers, arranged with fuel nozzles at swirler center. The annulus liner with swirlers and fuel nozzles develop circumferential flame front. The primary reaction region is defined downstream of the swirlers and, the reaction region is divided into two regions separated by Variable Cross-section type arrangement. The reaction region before Variable Cross-section is operated at fuel rich condition, whereas after Variable Cross-section, the reaction region operates at fuel lean condition. The transition from fuel rich to fuel lean reaction region is accomplished by introducing large amount of air at throat of the Variable Cross-section, leading to high velocities and flame quenching, eventually leading to slow deflagration flame. Such condition leads to two stages of combustion, one being the rich combustion, and another being the lean combustion. Such stage combustion leads to reduction in Nitrogen oxides formation (NOx). Downstream of primary reaction region is the dilution region, wherein the products of combustion are diluted with air, thereby reducing the temperature and generating a near uniform temperature profile at exit. Due to reaction temperatures being high, annulus liner walls are cooled by admission of air through holes on the liner walls.