Experimental Study On Atomization Characteristics Of Gas-liquid Two-phase Flow Nozzle Under Different Ambient Pressure

Shell coal gasification technology has been widely used because of its high conversion rate, but synthetic gas quench technology is expensive,what's more, abrasion and corrosion make it worse.Gas-liquid two-phase flow quenching method can solve the problem effectively.At present,there are few experiments studied about the characteristics of effervescent atomization under high back pressure.In this paper, we chose Gas-liquid two-phase flow quenching for Shell coal gasification furnace as background,and proposed a gas-liquid two-phase quench nozzle based on effervescent atomization technology.And we conducted a lot of experiments to study the influence of various factors on the characteristics of effervescent atomization.Firstly this paper conducted a lot of experiments of effervescent atomization about SMD, to study the influence of various factors on the atomized droplets size.It suggest that the gas-liquid mass ratio(GLR) and injection pressure has great influence on the SMD,and the SMD is both decreased by the increase of GLR and injection pressure.Jet velocity and nozzle exit diameter have less effect on the SMD, SMD decreases by the increasing of the jet velocity,and increase by the increasing of exit diameter.Along the jet axis direction, the farther the distance from the nozzle exit, the bigger SMD will be, and the large size particles increased rapidly in the location where closed to the exit.Because the nozzle's actual working environment is not under normal pressure, so conducted some experiments under high back pressure to research the characteristics of effervescent atomization.The influence of various factors on the spray cone Angle and the flow characteristics of the nozzle were studied in these experiments.We found that if one phase's mass flow remained constant, the pressure difference when another phase's mass flow achieved the same numerical is more and more small with the increasing of the ambient pressure. GLR has much effect on the spray cone angle,and the spray cone angle always increased with the increasing of GLR.Jet velocity have little effect on the spray cone angle,and the spray cone angle increased slightly with the increasing of the jet velocity.The influence of ambient pressure on the spray cone angle is also very big, the spray cone angledecreased initially as the ambient pressure is increased from 0.4 to1.0 MPa,and increased thereafter with a further rise in the ambient pressure.