Keywords: gas turbine fuels, second law efficiency, exergy analysis, combined cycle, power generation, gas turbines, Brayton combined cycle, paraffinic fuels, methane, heptane, hydrocarbons, alternative fuels
Efficiency of a standard gas-turbine power generation cycle running on different fuels
This paper presents a study of second-law efficiency in a standard Brayton combined cycle power generation, using several paraffinic fuels ranging from methane to heptane. The main objective of the study was to identify a trend with the number of carbon atoms in the compound. In this way, a qualitative criterion can be built to evaluate the properties of poor-quality gas turbine fuels containing significant amounts of C
2+hydrocarbons from the point of view of exergy. This is important in the current energetic scenario, where new blends are being studied as alternative to natural gas for economic, environmental or availability reasons. The results show a decreasing trend in exergetic efficiency with heavier compounds.