Improvement in performance of the boilers in 4th refinery of south pars gas complex by energy and exergy analysis

In this paper, improving the performance of the boilers 4th refinery of south pars gas complex, using energy and exergy analysis is discussed. After modeling the factors affecting the performance boilers of the refinery such as variations in ambient temperature, relative humidity, percent excess air and preheat boiler feed water are investigated. According to the results of thermal efficiency and exergy efficiency of 4the boilers 4th refinery operating conditions (ambient temperature 25 , relative humidity of 70 % air and excess air of 35 %), respectively 75.78 % and 39.64 % has been obtained, Also by setting the percentage of excess air in the combustion chamber of the boiler, exergy efficiency of the boiler can be increased to 41.46%.