Effect of water content on heat efficiency and NOx emission in water fuel emulsion combustion

摘要

Water fuel emulsion consists of base fuel,water and a trace of surfactant.The combustion of emulsified fuel associates an interesting phenomenon called micro-explosion. Micro-explosion enables simultaneous reduction of emissions of both nitrogen oxides and particulate matter.However,there are certain concerns about the thermal efficiency which may be deteriorated by the lowered combustion temperature due to the addition of water.In this study,emulsified fuel mainly consists of water and heavy oil A was burned in a test furnace with minimum air ratio that ensured no CO emission.The complete combustion of the base heavy oil required an air ratio of 1.4.On the contrary,the emulsified fuel with water content of 30 wt%required an air ratio of only 1.05 for complete combustion,resulting in the decrease in the amount of flue gas.The decreased amount of flue gas then resulted in the increase in furnace temperature and the decrease in energy loss carried away with the flue gas.The NOx emission was also decreased with the emulsified fuel.Combustion of emulsified fuel with minimum air feed rate which ensures the complete combustion is highly promising to maximize fuel utilization efficiency and minimize pollutant emissions simultaneously.