摘要
为开发汽油压燃(GCI)发动机可靠冷启动技术,采用实验和数值模拟结合方法研究了汽油、乙醚及其掺混燃料(掺混比为10%~50%)在不同工况下的喷雾发展及蒸发特性。结果表明,可视化实验及数值模拟获得的喷雾宏观形貌及液相截面落点分布结果吻合良好,且随着乙醚掺混比例的增加,喷雾贯穿距离与喷雾锥角增加幅度最高分别可达20%、10%,喷雾的粒径略有减小,但喷雾的蒸发程度明显增大;基于挂滴法开展的燃料液滴蒸发特性实验证实了乙醚掺混对于掺混燃料的蒸发具有显著促进作用;相同工况下,不同掺混百分比的掺混燃料的蒸发速率均先增大后减小,相比于汽油能够更快达到峰值,并且随着乙醚掺混比的提高,燃料喷雾蒸发速率得到了明显提高。结合实验与模拟研究结果,认为通过掺混高活性的乙醚,在提高汽油燃料雾化质量的同时,能够大幅提升燃油的蒸发速率,从而帮助提高缸内可燃混合气的形成质量,有望克服GCI发动机冷启动性能差的缺点。
To improve the cold start performance of gasoline compression ignition(GCI)engines,the spray development and evaporation characteristics of gasoline,diethyl ether and their blended fuel(with a volume fraction of 10%-50%)under different operating conditions were studied by visual experiments and numerical simulation.The results show that the numerical simulation is in good agreement with the experimental results in spray macroscopic morphology and liquid phase cross-section area.The numerical simulation results show that as the diethyl ether mixing ratio increases,the spray tip penetration distance and spray cone angle slightly increase by up to 20%and 10%,respectively,the particle size of spray slightly decreases,but the spray evaporation significantly increases.The fuel droplet evaporation characteristics experiments using the suspension method have confirmed that diethyl ether mixing has accelerated the evaporation of blended fuel.The evaporation rate of diethyl ether and all blended fuels increases first and then decreases,reaching the maximum evaporation rate earlier than gasoline.With the increase of diethyl ether mixing ratio,the evaporation rate of fuel spray is significantly increased.Based on the experimental and numerical simulation results,it is believed that by mixing diethyl ether,the atomization quality of gasoline fuel can be improved,while the evaporation rate of fuel spray can be significantly increased,thus improving the quality of mixture formed in the cylinder,and helping to improve the cold start performance of the GCI engine.
作者
姚晓新
尤冠文
罗坤
童尚庆
汤成龙
YAO Xiaoxin;YOU Guanwen;LUO Kun;TONG Shangqing;TANG Chenglong(School of Energy and Power Engineering,Xi’an Jiaotong University,Xi’an 710049,China;China National Heavy Duty Truck Group Co.,Ltd.,Jinan 250100,China)
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2023年第12期90-101,共12页
Journal of Xi'an Jiaotong University
基金
国家自然科学基金资助项目(52236001)。
关键词
汽油压燃发动机
二乙醚
喷雾
数值模拟
蒸发特性
gasoline compression ignition engine
diethyl ether
spray
numerical simulation
evaporation characteristics
