Use of Fuzzy Logic to Control Air Intake for Increase in Boiler Efficiency

Abstract

This paper presents a study and investigation of an improvement of boiler efficiency with an automatic control of air quantity into a combustion chamber. A fire tube boiler with a fixed gate and screw conveyor for feeding fuel was used to test the automatic control system, and a sub-bituminous was used as a fuel for this study. The increase in boiler efficiency was based on controlling amount of air quantity for fuel combustion before entering to the combustion chamber using fuzzy logic control algorithm. Automatic combustion control was achieved by measuring the amount of Oxygen gas (O2) from flue gas stack. From the experimental results, it was indicated that the automatic control system can control the average amount of O2 in flue gas at 11.09% when the O2 in the flue gas was set at 10%. The boiler efficiency was increased by 4.34%, and the energy consumption was reduced to have a fuel saving of 195.88 ton/year.