Conventional and Advanced Exergy Analysis of Air-Film Blade Cooled Gas Turbine Cycle

Air-film blade cooling is widely used gas turbine blade cooling technique. The present paper carries out conventional as well as advanced exergy analysis of air-film blade cooled gas turbine cycle based on a film cooling model which takes into account the effect of radiative heat transfer from hot combustion gases to gas turbine blade surface. From the basic concept of thermodynamics, it is well known that the rise in temperature at which heat is added in a cycle results in an increase in thermal efficiency. This could be possible by increasing turbine inlet temperature (TIT) for a fixed maximum allowable blade temperature. The study further analyses air-film blade cooled gas turbine cycle thermodynamically and further carries out conventional and advanced exergy analysis. The study shows that component-wise exergetic efficiency has been observed as 97.5, 80.2, and 91.4% for AC, CC, and GT, respectively, while exergy efficiency for gas turbine cycle is observed to be 37.43%. The maximum exergy destruction has been observed for CC ~ 251.5 kW. The results of advanced exergy analysis show that most of the exergy destruction within cycle components is endogenous. This is indicative of weak mutual interactions between cycle components. The study further shows that ~81.2% of exergy destruction for cycle is unavoidable which indicates the least improvement potential for cycle.