Abstract

Gaseous fuels obtained through biomass conversion processes such as gasification, pyrolysis and pyrogasification are generally defined as synthesis gas. Due to the large difference between synthesis gas and traditional fuels characteristics, the use of synthesis gas in small-size energy systems, has not yet reached a level of technological maturity that could allow a large market diffusion. For this reason, further analyses have to be carried out to allow these technologies to achieve performance and reliability typical of established technologies based on traditional fuels.
In this work, a CFD analysis of the combustion chamber of a 100 kWel nominal power micro gas turbine fed by a typical synthesis gas derived from biomass pyrolysis is presented. Firstly, three-dimensional numerical simulations were performed with ANSYS CFX 13.0 to identify the main features of combustion phenomena in case of syngas feeding with respect to natural gas feeding, for which the combustor has been designed. Then, the combustor geometry was slightly modified to account for synthesis gas operation and a simulation campaign was conducted. The purpose of the investigation is the analysis of the influence, in terms of combustion process and combustor performances, of the combustor geometry modifications in the case of synthesis gas feeding.