Small Industrial Gas Turbine Combustor Performance With Low BTU Gas Fuels

Abstract

To permit the use of gasifier-generated low BTU gas fuels in the LM500 engine, a modified version of its existing combustor was defined and tested. The LM500 engine is a small aircraft-derivative engine in the four megawatt class and is used in a variety of industrial applications. The combustor of this engine consists of a short-length and compact annular design with 18 fuel injectors. To accommodate the high volumetric flow rates associated with the use of low BTU gas fuels, a modified fuel injector configuration was defined. With this modified configuration, the combustor was found to operate satisfactorily with low BTU gases over a wide range of heating values. Stable combustion was obtained with fuels having heating values as low as 3.72 MJ/m3 (100 BTU/SCF). Also, acceptable combustion efficiency levels and exit temperature distributions were obtained. Based on these results, it is concluded that the LM500 engine can satisfactorily accommodate low BTU gas fuels typical of those produced by coal or biomass gasifiers and by other industrial processes.