A study of combustion characteristics and reduction of combustion products for swirl burner by using dilute ethanol water solution

Abstract

In recent years, ethanol has attracted attention as an environmentally substitute fuel because of exhaustion of petroleum resources and environmental issues. In this study, we investigated emission by using the ethanol water solution from 45 to 60 vol.% concentrations under continuous combustion region by using the swirl burner. In addition, we investigated the flame behavior, influence of flame shape and flame length on the exhaust gas temperature and reduction of emission such as CO and NO_X. Furthermore, the influence of the swirl flow by the supply air on the spray shape and the influence of the liquid film on the combustion characteristics were also examined. The exhaust gas temperature was measured in a combustion chamber and exhaust pipe by using K type thermocouples. The main conclusion are as follows: 1) The liquid film/liquid column ratio near the nozzle increases with decreasing the spray angle and the fuel flow rate at the low ethanol water solution (E45). 2) The continuous combustible regions are bigger with increasing the fuel flow rate at the low ethanol water solution (E45). 3) The exhaust gas temperature decreases monotonically with increasing the air ratio in spite of the spray angle and the fuel flow rate at low ethanol water solution (E45, E60). 4) The CO emission of high fuel flow rate remarkably decreases than that of low fuel flow rate at any spray angle for the ethanol water solution (E60) under the air ratio λ from 1 to 1.4. 5) It is possible to realize the less than 10 ppm NO_X emission by using the ethanol water solution of E60 under the wide range of air ratios. 6) It is possible to reduce the simultaneous reduction of CO and NO_X emissions for the ethanol water solution (E60) under the high air ratio.