Study On Atomization Characteristics Of Fluid Dynamic Ultrasonic Fuel-Oil Burner

The application situation and problems of fuel-oil burner were summarized in this paper. Based on the analysis, the principle of fluid dynamic ultrasonic fuel-oil burner was introduced and a kind of ultrasonic fuel-oil burner was designed, then spray experiment and numerical simulation of cold flow process were conducted.Through spray experiments, the influence of pressure of the atomization air, oil pressure, air-liquid-rate(ALR) and oil temperature (viscosity) on atomization diameter and atomization angle was analyzed. The experiments results show that: the fluid dynamic ultrasonic fuel-oil burner had a good atomization effect on both heavy oil and residual oil, with the increase of pressure of the atomization air, both the atomization diameter and atomization angle decreased, and the higher of the air pressure, the weaker trend of decrease; with the increase of pressure of oil, both the atomization diameter and atomization angle increased, and the higher of the oil pressure, the weaker trend of increased; both atomization diameter and atomization angle decreased with the ALR increasing, but when ALR increases to a certain number, both of them would have little change, and this ALR regards as the best one; atomization diameter of heavy oil and residual oil decreased with temperature increasing, when heavy oil temperature achieves 90℃, atomization diameter decreases to below 30?m.Based on the spray experiments, the corresponding air distribution device for fluid dynamic ultrasonic fuel-oil burner was designed, which is one type of axial movable impeller. Impeller position was changed by moving the pull rod, when which was pulled forth, a part of air came into firebox through the annular clearance outside the impeller, when which was moved forward-backward, swirl intensity was regulated through changing swirling air-straight air-ratio. Based on the spray experiments and the design of air distribution devices, then numerical simulation of cold flow process was done, which was mainly focused on the influence of swirl intensity of secondary air on flow field and distribution of atomization droplet. The simulation result shows that the stronger swirl intensity becomes, the stronger influences on atomization droplets has, and the more uniformly secondary air and atomization droplets mix.The study on the spray experiments and numerical simulation of cold flow process of fluid dynamic ultrasonic fuel-oil burner shows that the fuel-oil burner has a good atomization effect on low-grade fuel. The paper summarized characteristics of fluid dynamic ultrasonic fuel-oil burner, analyzed the advantages and disadvantages of the fuel-oil burner, and put up advices for the design of fluid dynamic ultrasonic fuel-oil burner.