Analytical modeling and assessment of overspray fogging process in gas turbine systems

In this study, analysis of the overspray fogging process, which consists of inlet fogging and wet compression processes in gas turbine cycle, is carried out with a non-equilibrium analytical modeling based on liquid droplet evaporation. The transient behaviors of droplet diameter and air temperature are examined. Special attention is paid to the effects of system parameters such as pressure ratio, water injection ratio, and initial droplet diameter on the process performances, including evaporation time of droplets, compressor outlet temperature, and compression work. Process performances are also estimated under the condition of critical water injection ratio above which complete evaporation of injected water droplets within a compressor is not possible. The analytical results indicate that the overspray fogging process has a potential of lowering compressor outlet temperature and saving significant compression work when compared to dry compression, and this technique is more effective for a higher pressure ratio and smaller size of injected water droplet.