Development of light-oil burner for heating exhaust gas of diesel engine

Abstract

A lab-scale two-stage light-oil burner has been developed to obtain the fundamental data required for designing burners to heat a diesel particulate filter when exhaust gas temperature of the main engine is low. Regenerative-heating and pre-evaporation premixing combustion were adopted to this burner for downsizing and reducing cost. Two-stage combustion was realized in the burner to reduce the heat-load of the combustion chamber for the first stage combustion. The combustion chamber volume is about 66 mL. Observations of flame-holding condition and temperature measurements of the burner and combustion gas were performed with varying the fuel flow rate and air flow rate. Three types of secondary air nozzle and three secondary air nozzle positions were tested to understand the effect of the secondary nozzle on combustion gas temperature and combustion gas compositions. It was found that the burner in the single-stage combustion mode was able to stabilize a flame in the range of 2 to 14 mL/min in fuel flow rate at adequate equivalence ratio in the range of 1.4 to 1.8. Combustion gas temperature of the burner in the two-stage combustion mode is determined by the total equivalence ration and is independent on the equivalence ratio of the first stage combustion. It is possible to suppress CO and NOx emissions when the burner is operated at 0.8 in the total equivalence ratio.