| CWS gasification technology is one of the hot spot of Clean Coal Use(CCU) technologies. Compared with other CCU tecnologies, it is brought into China much earlier and has got much more progress.But there're many problems still existed, of which CWS nozzle technology is the bottleback of CWS gasification technology development. Three-channel external mixing type nozzle is the most widely used in today's China. It's meaningful to study the atomization performance of the three-channel external mixing type nozzle under high ambient pressure. This paper is based on the research work and mainly contains two sections:1.Experiment. First, the paper studies the flow characteristics of the three-channel external mixing type nozzle under high ambient pressure. Second, taking droplet size SMD as the estimate target, the paper studies the effects of both the structure and sizes of the nozzle towards the atomization performance. Also taking droplet size SMD as the estimate target, the paper studies the effect of operation parameters in different ambient pressures and analyzes the reason. Then, the paper analyzes photos of the spray and measures the spray angles under different ambient pressures and air/liquid ratios. Finally, the effects of the liquid viscosity under different ambient pressures towards the atomization performance is discussed.2.Numerical Simulation. Based on the cold-state experiment, numerical simulation is introduced. First, the paper set up 3-D physical model of the three-channel external mixing type nozzle and then analyzes the characteristics of velocity field, pressure field and the reflux area by simulating the distribution of flow field with k-s two-way model.Second, the paper analyzes the atomization field outside the tip of the nozzle with LES and DPM model under unsteady environment. The result is of practical significance for the design of nozzle.
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