自吸入式气液两相流喷头设计与关键结构参数优化

Design and Optimization of Key Structural Parameters for Self-aspirating Gas-Liquid Two-phase Flow Nozzle

摘要:

针对大田喷雾作业中喷洒液体利用率低和环境污染严重等问题,本文设计了一种自吸入式气液两相流喷头。采用单因素控制变量试验,分析工作压力、驱动喷嘴出口直径、吸气口数量以及V形槽切角对喷雾性能的影响。试验结果表明,压力升高会显著增大喷头流量、飘移量与沉积量,但也导致飘移潜力显著上升,尤其在侧风条件下更为明显;当压力为0.2 MPa时能在沉积性能与飘移控制之间取得较好平衡。气液两相流作用提升了喷洒液体沉积效率,驱动喷嘴出口直径和V形槽切角对雾化性能具有显著影响。喷雾角和沉积量均随出口直径增大而增大。当吸气口数量为2时,沉积量较单相流喷头提升14.0%。V形槽切角为20°时喷雾角最大,15°时防飘移性能最优。通过响应面试验及多目标优化获得了喷头最优参数组合,在压力0.2 MPa工况下喷雾角达90.20°且飘移潜力仅为6.35%,实现了宽喷雾角与低飘移潜力的协同优化。研究结果为大田喷雾作业提供了一种覆盖范围广、飘移损失小的解决方案。

Abstract:

Aiming to address issues such as low liquid utilization and severe environmental pollution in field spraying operations,a novel self-aspirating gas-liquid two-phase flow nozzle was designed. A single-factor controlled variable experiment was employed to analyze the effects of operating pressure,drive nozzle outlet diameter,suction inlet quantity,and V-groove cutting angle on spray performance. Experimental results indicated that increased pressure significantly enhanced nozzle flow rate,drift volume,and deposition rate,yet also led to a marked rise in drift potential,particularly under crosswind conditions. A pressure condition of 0.2 MPa achieved a favourable balance between deposition performance and drift control. The interaction between gas and liquid phases enhanced the deposition efficiency of sprayed liquids. The outlet diameter of the drive nozzle and the V-groove angle significantly influenced atomization performance. Both the spray angle and deposition rate were increased with large outlet diameters. With two air inlets,deposition was increased by 14.0% compared with that with single-phase flow nozzles. The spray angle reached its maximum at a V-groove angle of 20°,while a 15°angle exhibited optimal drift suppression performance. Through response surface experiments and multi-objective optimization,the optimal parameter combination for the nozzle was determined. At an operating pressure of 0.2 MPa,the spray angle reached 90.20° with a drift potential of merely 6.35%,achieving synergistic optimization of a wide spray angle and low drift potential. The research result can provide a solution for field spraying operations characterized by extensive coverage and minimal drift loss.