摘要
基于超声雾化技术,通过配比不同载气流量和燃料流量制备了四种当量比的正庚烷液滴流,利用Spraytec喷雾粒度分析仪确定其粒径分布,并在可控热氛围下对其稳态火焰特性进行了研究,分析了液滴流贯穿高度、火焰起升高度、火焰高度、火焰宽度等参数的变化规律。结果表明:液滴流燃烧时总体呈淡蓝色预混火焰,但液滴流浓度增大、热氛围温度升高时会产生暗红色尾焰;液滴流贯穿高度、火焰起升高度和火焰宽度都随热氛围温度升高而减小,而火焰高度随热氛围温度先降低后升高,且在高温区随当量比增大而升高;燃料流量增大使液滴流贯穿高度和火焰起升高度降低,使火焰宽度变小;载气流量增大使液滴流贯穿高度减小,使火焰起升高度在高温区减小,在低温区增大。
Based on ultrasonic atomization,n-heptane droplet streams of four different equivalence ratios were generated by varying the flow rates of carrier-air and fuel.The stream droplet size distributions were determined by Spraytec particle size analyzer.The streams were introduced into a controllable active thermo-atmosphere to study the flame characteristics,including the stream liquid penetration,the flame lift-off height,the flame height and the flame width.The experimental results showed that the combustion of streams presented generally pre-mixed blue flames,although a tail-like dull red flame zone attached to the top of the flame when increasing the equivalence ratio and thermo-atmosphere temperature.The liquid penetration,the flame lift-off height and width reduced with increasing thermo-atmosphere temperature and fuel flow rate,while the flame height went down at first and then went up with increasing temperatures,and at relatively higher temperatures,the flame height increased with increasing equivalence ratio.The increasing carrier-air flow rate decreased the stream liquid penetration,and reduced the flame lift-off height at relatively higher temperatures while doing the opposite at relatively lower temperatures.
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2016年第5期1134-1139,共6页
Journal of Engineering Thermophysics
基金
国家自然科学基金项目(No.51106113)
关键词
超声雾化
正庚烷
液滴流
粒径分布
火焰特性
ultrasonic atomization
n-heptane
droplet streams
droplet size distribution
flame characteristics
