Experimental study on binary droplet evaporation at elevated pressures and temperatures
Experimental study on binary droplet evaporation at elevated pressures and temperatures
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DOI：
10.1080/00102200500296697
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发表时间：
2006-06-01
影响因子：
1.9
通讯作者：
Khan, QS
中科院分区：
文献类型：
--
作者：
Ghassemi, H;Baek, SW;Khan, QS
在重力作用下，对石英纤维顶端悬挂的单组分和多组分液滴在不同环境条件下的蒸发特性进行了实验研究。选用正庚烷和正十六烷作为两种蒸发速率和沸腾温度不同的燃料。在第一步中，分别研究了两种燃料的单组分液滴的蒸发。在下一步骤中，已经研究了这两种燃料的几种混合物作为二元组分液滴的蒸发。温度和压力范围分别在400和700摄氏度之间以及0.1和2.5MPa之间选择。高温环境由下落式电炉提供。液滴初始直径在1.1 ~ 1.3mm之间，用高速CCD摄像机记录蒸发过程。二元液滴蒸发实验结果表明，蒸发过程分为三个阶段。在第一阶段，挥发性更强的组分蒸发。液滴温度上升后，几乎非蒸发期，在第三阶段，准线性蒸发发生。低压下二元液滴的蒸发伴随着气泡的形成和液滴的破碎，导致不完全微爆。组分浓度影响前两个阶段的蒸发行为。在较高的环境压力下，不会出现气泡形成和液滴变形。
The evaporation characteristics of single and multicomponent droplets hanging at the tip of a quartz fiber are studied experimentally at the different environmental conditions under normal gravity. Heptane and Hexadecane are selected as two fuels with different evaporation rates and boiling temperatures. At the first step, the evaporation of single component droplet of both fuels has been examined separately. At the next step the evaporation of several blends of these two fuels, as a binary component droplet, has been studied. The temperature and pressure range is selected between 400 and 700 degrees C, and 0.1 and 2.5 MPa, respectively. A high-temperature environment was provided by a falling electrical furnace. The initial diameter of droplet was in the range of 1.1 and 1.3 mm. The evaporation process was recorded by a high-speed CCD camera. The results of binary droplet evaporation show the three-stage evaporation. In the first stage the more volatile component evaporates. The droplet temperature rises after an almost non-evaporative period and, in the third stage, a quasi-linear evaporation takes place. The evaporation of the binary droplet at low pressure is accompanied with bubble formation and droplet fragmentation and leads to incomplete microexplosion. The component concentration affects the evaporation behavior of the first two stages. The bubble formation and droplet distortion does not appear at high environment pressure.