After fogging process in water injected gas turbine systems

Abstract

In gas turbine system with after fogging, water droplets are injected after compressor. After fogging could have more significant potential for enhancement of specific power production compared to inlet fogging alone, since a larger water injection rate is possible. Transient analysis of after fogging process is carried out by using a heat and mass transfer modeling on water droplet evaporation. Transient variables such as droplet diameter and air temperature are evaluated as the droplet evaporation proceeds for different values of initial droplet diameter, pressure ratio of compressor, and water injection ratio. The evaporation time for injected droplets are also estimated. Present results show that the evaporation time decreases sensitively with increasing pressure ratio or initial droplet diameter. However, the effect of water injection ratio on evaporation time is relatively insignificant unless water injection ratio is near the critical ratio.