新型气液混合喷油刀梁设计及数值模拟  

Design and numerical simulation of novel spraying blade for gas-liquid mixing

作　　者：汪朝晖[1] 高全杰 徐占民[1] 王维[1] 

机构地区：[1]武汉科技大学机械自动化学院,湖北武汉430081

出　　处：《排灌机械工程学报》2013年第3期236-241,共6页Journal of Drainage and Irrigation Machinery Engineering

基　　金：高等学校博士学科点专项科研基金资助项目(20124219120001);湖北省教育厅科学技术研究计划优秀中青年人才项目(Q20111108);武汉市学科带头人计划项目(201051730557)

摘　　要：针对传统刀梁采用单一防锈油液喷涂存在耗油量大、环境污染严重、表面雾滴沉积性及吸附性较差等缺陷,设计了新型气液混合静电喷油刀梁,建立了其几何模型及数学模型,确定了刀梁设计的关键计算参数.研究结果表明:气液相在新型喷油刀梁混合室产生旋涡流场,使得油液与气体充分混合与破碎,气液速度呈纵向轴对称分布,最大速度值和最小速度值分别为4.310m/s和0.287 m/s,最外层等值线处雾滴速度值约为0.293 m/s,且刀梁刃口雾滴速度均匀性较好,雾滴呈发散状分布,喷涂范围较宽;气液相经第2次混合,在刀梁引射区至刃口的渐宽缝隙中,雾滴速度逐渐降低,液相中较高压力的气体泡逐渐膨胀,使得雾滴进一步破碎;当喷涂仿真时间分别为0.000 1 s时和0.002 6 s时,刀梁刃口处雾滴最大粒径分别为70.76μm和32.94μm,随着仿真时间增大,雾滴粒径逐渐变小,分布趋于稳定,提高了气液相雾化效果和表面喷涂质量.A new type of gas-liquid mixing electrostatic spraying blade was designed to eliminate the drawbacks in the existing anti-rust oil spraying machines with a single oil spray, for instance, high oil consumption, serious environmental pollution, poor adsorption and deposition of spraying oil and so on. The geometric parameters and mathematical model for the spraying blade were established, thus its key design parameters were determined based on the structure of existing electrostatic spraying blade. It was shown that there is a vortex flow in the mixing chamber of the new spraying blade, causing the oil and gas are mixed thoroughly. The gas velocity is distributed axisymmetrically with 4.310 m/s ma- ximum and 0. 287 m/s minimum velocity in the chamber. The droplet velocity at the outermost contour line is about 0. 293 m/s. The droplet velocity is uniform at the outlet of the spraying blade and the droplets themselves are distributed divergently, leading to a relatively wide spraying range. After the second gas-oil mixing, the droplet velocity is lowered gradually in the divergent gap between the blade outlet and the second mixing chamber; the expandable gas bubbles induce the oil droplets to be broken once more. When the spraying simulation times are 0. 000 1 s and 0. 002 6 s, the maximum droplet size at the outlet of spraying blade are 70.76 μm and 32.94 μm, respectively. Additionally, with in-crease of simulation time, the distribution of droplet size becomes stable, suggesting the gas-liquid ato- mization effect and the quality of surface coating are improved greatly.

关 键 词：静电喷涂 气液混合 刀梁 设计 数值模拟 

分 类 号：S277.9[农业科学—农业水土工程] TP69[农业科学—农业工程]