Role of Cooling Techniques and Fuels in Enhancing Power and Efficiency of Gas Turbine Plants

Performance analysis of different gas turbine power plant configurations is presented in this paper. The work includes the effect of humidity, ambient inlet air temperature and types of fuels on gas turbine plant configurations with and without cooling technologies. Investigation also covers economic analysis. 20 MWe GE 5271RA and 40 MWe GE-6561B frames are selected for the present study. GT PRO software has been used for carrying out the simulations for a given location of Saudi Arabia. The relative humidity and temperature have been varied from 30 to 45 % and from 80 to 100° F, respectively. Fuels considered in the study are natural gas, diesel and heavy bunker oil. Results show that variation of humidity does not affect the gas turbine performance for all types of fuels. For GT only situation, for a decrease of ambient inlet air temperature by 10 °F, plant net output and efficiency have been found to increase by 4%, 1 % respectively, for all fuels. However, with addition of, fogger, plant net output and efficiency further increase by 3 %, 1% respectively. For all GT frames with fogger, the net plant output and efficiency are relatively higher as compared to GT only case for all fuels. The net plant output and efficiency for natural gas are higher as compare to other fuels for all GT scenarios. For 40 MWe frame with and without fogger, break even fuel price and electricity price have been found to vary from 2.03 to 2.22 USD/MMBTU and from 0.024 to 0.026 USD/kWh respectively.