海拔高程对泄洪雾化影响的敏感分析

针对海拔高程对于泄洪雾化降雨分布的影响,提出了一种改进的随机溅水数学模型。运用小湾水电站泄洪洞雾化实测降雨资料进行模型验证,两者结果吻合良好。敏感分析表明,随着海拔高程的增加,泄洪洞下游雾化降雨范围有增大的趋势,当海拔高程从50 m增加到3000 m时,泄洪雾化雨区在两岸的爬升高度增加50 m,纵向范围增大100 m;同时,降雨强度等值线分布发生坦化,在降雨强度大于400 mm/h的等值线区域,分布范围缩小,而在400 mm/h以下区域,雨区分布范围明显增大。上述研究为今后全面考虑海拔高程与气象条件对于泄洪雾化过程的影响建立了基础。     

采用石灰浆液荷电雾化的脱硫机理试验研究

采用环形电极、机械雾化喷嘴等组成的荷电雾化装置,通过测试石灰浆液的荷质比、喷浆脱硫前后烟气中二氧化硫浓度的变化,探讨和分析了不同流量时的荷质比变化规律,首次对不同荷电电压、荷质比与脱硫效率的关系进行研究.结果表明:雾滴的荷电效果与浆液流量有关,且对于同一喷嘴存在荷电效果最佳的流量值;在相同钙硫比条件下,浆液荷电相对于非荷电时脱硫率明显提高;在不同钙硫比情况下,浆液荷电与非荷电的脱硫率变化趋势基本相同.     

垃圾焚烧烟气旋转喷雾干燥净化的实验研究

针对垃圾焚烧烟气量小、组分中SO2较少、HC1较多的特点,建立了垃圾焚烧烟气旋转喷雾干燥法净化实验系统,并测试了在系统设计和运行中主要可控参数对脱硫脱氯效率的影响.结果表明:旋转喷雾干燥法对HCI的脱除率较高,对SO2的脱除率较低,但可满足对垃圾焚烧烟气中SO2浓度的要求,同时可以保证较高的脱氯效率,特别适用于垃圾焚烧烟气净化;提高化学计量比、喷水量、喷雾器转速,降低烟气流速都可以提高脱酸效率.     

船用增压锅炉旋流蒸汽机械喷油器的雾化特性

采用LPI-3衍射式激光粒子测径仪与LE-3雾化角测量仪对船用旋流蒸汽机械雾化喷油器进行了试验研究,得到了雾化油滴索特平均直径及喷油量与压力的变化关系;利用Realizable k-ε模型模拟气体湍流流动,随机轨道模型模拟液滴运动;并用LISA模型和TAB模型模拟液滴变形和破碎,对旋流蒸汽机械雾化喷油器的雾化过程进行了数值模拟,分析了喷油器内雾化空气和油质量流量对雾化特性的影响,模拟的结果与试验结果吻合得较好。研究表明,在喷油压力高于1.1MPa时,喷油器特性符合机械雾化喷嘴的一般规律,但当喷油压力较低时,雾化规律相反,喷油压力越低,雾化粒度越细。由此表明,旋流蒸汽机械雾化喷油器可以极大地改善低工况雾化质量,具有较大的调节比,气耗量也优于常见的气动雾化喷油器。     

催化裂化进料喷嘴压降分级结构对其雾化效果的影响

压降是喷嘴雾化的原动力。喷嘴各级结构和雾化原理不同,其雾化效率就存在差异。采用具有不同压降分级结构的喷嘴进行了多种工况下的雾化实验,利用LS-2000型激光粒度仪对雾化场进行了测量。结果表明,喷头段雾化效率明显高于喷嘴其他各段;当喷头段压降占总压降的比值增大时,喷雾粒径变小;当喷头段压降与总压降的比值约为0.7时,喷嘴雾化效率较优。     

含碳颗粒的凝胶推进剂雾化特性实验研究

固体含能颗粒对提高凝胶推进剂的能量特性具有重要作用,是凝胶推进剂的重要组成部分。雾化问题是凝胶推进技术的关键问题之一,为了研究添加固体含能颗粒对凝胶推进剂雾化的影响,选择碳颗粒作为固体添加剂,开展了含碳颗粒凝胶推进剂雾化的实验研究。制备了3种不同含碳颗粒凝胶推进剂模拟液,并对它们的流变和触变特性进行了测量;分析了不同射流速度、不同撞击角度下的雾化场特点和形成机理,以及撞击速度对雾化模式,撞击角度对雾化场基本形状,碳颗粒质量分数、平均粒径等因素对模拟液流变特性和雾化效果的影响;提出了一种基于尺度不变特征变换关键点匹配的雾化场速度计算方法,定量分析了含碳颗粒凝胶推进剂的雾化场速度;以雾化场速度分析为基础提出了一种新的液膜厚度估算方法。研究结果表明：雾化效果随着射流速度和撞击角度的增大而显著改善;碳颗粒的添加对雾化效果有着重要影响,雾化效果随着碳颗粒质量分数的增大而降低,适当增大碳颗粒的粒径可以改善雾化效果;雾化场平均速度与射流速度的比值v_a/v_j可以用于表征雾化效果,v_a/v_j越小,能量转换效率越高,雾化效果越好。     

Hydriding behavior in Zr-based AB2 alloy by gas atomization process

The hydriding characteristics of Zr-based AB₂ alloy produced by gas atomization have been investigated during its absorption–desorption reaction with hydrogen gas. Its gas-phase hydrogenation properties are different from those of specimens prepared by conventional methods. For the particle morphology of the as-cast and gas-atomized powders, it can be seen that the mechanically crushed powders are irregular, while the atomized powder particles are spherical. In PCT (Pressure–Composition–Temperature) measurements, for the gas-atomized particles smaller than 50 μm, the hydrogen storage capacity is dramatically decreased and the hysteresis loop becomes larger than that of the gas-atomized particles larger than 50 μm. In addition, the increase of jet pressure of gas atomization results in the decrease of hydrogen storage capacity and the slope of plateau pressure significantly increases. TEM and EDS studies showed the increase of jet pressure in the atomization process accelerated the phase separation within grain of the gas-atomized alloy, which brought about a poor hydrogenation property. In the measurements of hydrogen absorption–desorption kinetics, the improvement of desorption kinetics of gas-atomized AB₂ alloys was mainly caused by the higher plateau pressure, which is attributed to the smaller grain size and higher site energy for hydrogen in the gas-atomized alloys.     

Electrostatic emulsification of domestic and personal care products

A technique is described for producing high quality emulsions in a controllable and reproducible way. The dispersed liquid phase is atomized electrostatically, thus enabling particle size to be well below 10μm for wax solutions while at the same time maintaining a very narrow particle size distribution. The energy saving over conventional emulsification methods is considerable, amounting to up to 85% for one typical domestic care product.
Emulsification is achieved in a one-step process in a machine which essentially has no moving parts and requires no auxiliary air supply. In addition to the ability to create high quality emulsions, electrostatic atomization of the dispersed phase itself introduces a new and useful parameter, electrical conductivity, enabling greater flexibility in terms of ensuring emulsion stability. Even in conventional emulsifier systems, electrically charging the dispersed phase may have important implications which have not to date been fully appreciated.
Emulsification de produits de soins de la peau et de produits de ménage par une méthode électrostatique     

气体雾化过程几个重要参量的计算

利用流体力学理论，对气体雾化过程的气体出口速度、气体质量流率及金属质量流率等几个重要参量进行了分析，并给出了相关的数学表达式。     

Numerical Study on the Effect of Cavitation on Flow and Diesel Fuel Atomization Characteristics

Computational fluid dynamics (CFD) models based on the turbulent mixture multiphase model were applied to consider the effect of cavitation on the spray of diesel fuel. The effects of injection pressure and length‐to‐width (L/W) ratio on the velocity distribution, cavitation number, discharged coefficient, and nozzle exit velocity were investigated and the performance of the model was compared with the experimental data. The results indicate that the cavitation generated in the nozzle has a strong impact on the fuel injection and spray quality, whereas the L/W ratio is a highly effective parameter for cavitation behavior. In addition, by increasing the L/W ratio, the range of cavitation number, wall friction, and flow resistance increase but in the cavitation region the velocity profile in radial and axial directions, spray cone angle, nozzle exit velocity, and the discharged coefficient decrease.