对于间距为1.167的三角形和旋转三角形管布置的制冷剂R-123和R-134a，蒸发器管束中出现的液滴分布具有特征。本研究的目的是提高对液滴喷射过程的理解，以帮助设计大型制冷系统中常用的蒸发器。阴影照相装置中的激光和摄像系统在不同条件下拍摄了蒸发器顶部空间的图像。传统的阴影技术被用于识别液滴并匹配液滴进行速度计算。 蒸发器的条件各不相同，质量通量为3.5至40.7 kg/s-m²（2250至30000 lb/hr ft²），顶层热通量为5.3至31.5 kW/m²（1700至10000 Btu/hr ft²），出口饱和温度为4.4和12.8°C（40和55°F）。顶排的情况从淹水到干涸不等。给出了颗粒数、粒径分布和速度。还提供了顶空中计算出的液体体积分数，数值范围为0至10%。研究发现，尽管质量流量、饱和温度、热流密度和液位都很重要，但液体在顶空中的分布是各种性质的函数，其中制冷剂的选择最为重要。 蒸汽剪切被认为是导致大部分液滴生成的原因，尤其是在顶部空间。R-123的高液气密度比和相应的高流速使得在液滴脱离管束之前分离液滴特别困难。Zip文件包含报告和附录。（542MB）

The distribution of liquid droplets emerging from an evaporator tube bundle is characterized for refrigerants R-123 and R-134a with triangular and rotated triangular tube arrangements of pitch 1.167. The purpose of this research is to improve the understanding of the droplet ejection process to aid in the design of evaporators typically used in larger chiller systems. A laser and camera system in a shadowgraphy arrangement captured images of the evaporator headspace at varying conditions. Conventional shadowgraphy techniques were applied to recognize droplets and match droplets for velocity calculations. The evaporator conditions were varied with mass fluxes from 3.5 to 40.7 kg/s-m2(2250 to 30000 lb/hr-ft2), toprows heat fluxes from 5.3 to 31.5 kW/m2(1700 to 10000 Btu/hr-ft2), and outlet saturation temperatures of 4.4 and 12.8 °C (40 and 55 °F). Conditions ranged from flooded to dryout on the top rows. Particle number count, size distribution, and velocity are presented. The calculated liquid volume fraction in the headspace is also presented, ranging in value from 0 to 10%. Liquid distribution in the headspace is found to be a function of all varied properties, most strongly choice of refrigerant, though mass flux, saturation temperature, heat flux, and liquid level all matter. Vapor shear is thought to lead to the majority of droplets generated, especially in the upper headspace. The high liquid-vapor density ratio of R-123 and corresponding high velocities make it particularly difficult to separate liquid droplets before they escape the tube bundle.Zip file contains report and appendices. (542 MB)