Exergy Cost Analysis of New Method for Efficiency Improvement in Small Gas Turbines Using LNG Cold Exergy

Abstract

The gas turbine systems are some equipment; that have extensive industrial and military applications due to their unique characteristics. One of the major problems in association with utilization of gas turbines is the output power and thermal efficiency. One of the major methods that are used for increasing the power and thermal efficiency in this type of power systems is compressor's inlet air cooling. In this paper, the effect of fuel replacement for methane gasfired gas turbines with LNG and cooling the compressor's air inlet with the cold exergy of LNG fuel evaporation will be examined. In the first step, the energy balance equation is applied to the gas turbine with Methane and LNG fuel separately. Then the problem of fuel replacement in some mini and micro gas turbine has been examined and the appropriate engine with the most power and thermal efficiency is selected. In the next step, the exergetic analysis of considered systems is performed and exergetic parameters of the two systems are compared together. Finally, the advance exergy analysis is performed and effects of fuel replacement on exergetic cost parameter and environmental characteristics are evaluated.