Detailed exergetic evaluation of heavy-duty gas turbine systems running on natural gas and syngas

In the second case considered here (use of syngas instead of natural gas), the effects of mixing and adding excess air become more significant due to a higher specific heat capacity of the combustion gas. In both cases, the exergy destruction associated with mixing at different compositions can be neglected except the one at the inlet of the pre-mixed combustor, which strongly depends on the particular conditions of the fuel gas. Inefficiencies such as convective cooling of the vanes and blades, heat loss, losses associated with the shaft and generator were found to represent a very small part of the overall exergy destruction. The resulting exergy destructions and losses are shown in an exergy flow diagram.