多点同步采样测量柴油喷雾火焰中的碳烟形貌分布  

Soot Morphology Distribution in Diesel Spray Flame via Multi-Point Synchronous Sampling

作　　者：颜方沁[1] 成晓北[1] 邱亮[1] 黄荣华[1] 黄胜[1] Yan Fangqin;Cheng Xiaobei;Qiu Liang;Huang Ronghua;Huang Sheng(School of Energy and Power Engineering,Huazhong University of Science and Technology,Wuhan 430074,China)

机构地区：[1]华中科技大学能源与动力工程学院,武汉430074

出　　处：《燃烧科学与技术》2018年第1期67-74,共8页Journal of Combustion Science and Technology

基　　金：国家自然科学基金资助项目(51576083)

摘　　要：在定容燃烧弹内模拟内燃机喷雾燃烧工作条件,设计了定容燃烧弹内多点同步碳烟采样台架,对高压和低压两种环境下的喷雾火焰中生成的碳烟颗粒进行全场多点采样,利用高分辨透射电镜(HRTEM)对碳烟样本进行观测和图像处理、统计及分析.结合对喷雾火焰发展过程的分析,研究碳烟颗粒在整个喷雾火焰中的分布规律和主要影响因素.研究结果表明,火焰中碳烟颗粒主要以基本颗粒和小积聚颗粒的形式存在,平均粒径小于80,nm.积聚反应主要受到碳烟体积分数和环境温度的影响,碳烟的积聚化程度随着燃烧反应的进行不断增大.固体碳烟体积分数在喷雾火焰中心位置体积分数最高,在火焰外围体积分数相对较低.高压环境下碳烟体积分数远大于低压环境,且在喷雾火焰下游碳烟形貌的演变规律也不同于低压环境.碳烟的数量、质量、粒径与结构与喷雾火焰燃烧发展过程紧密相关.Multi-point synchronous thermophoretic soot sampling was carried out in a constant volume combustion chamber to obtain more information about soot morphology and size distribution in diesel spray flame.Two operation conditions were adopted to simulate heavy load high speed and light load low speed diesel engine combustion environment.A high-speed digital schlieren optical diagnostic system(HRTEM)was equipped for combustion flame recording and observation.Subsequent image processing and soot characteristic parameter statistics gatherins were performed.Soot morphology and size distribution regularity in cone-shaped diesel spray flame were concluded with combustion status diagnoses.Detailed soot distribution and evolution regularity in both spray centerline horizontal direction and radial direction were gained by experimental results.The result shows that in-flame soot mainly exists in the form of primary particle and small aggregation particle,normally smaller than 80,nm.Aggregation reaction is affected by soot density and ambient temperature,proceeding with combustion.Solid soot concentration is large in the center of spray flame center,but small in the peripheral area.The soot concentration in high pressure condition,is larger than that in low pressure condition,besides,the soot distribution regularity is different,too.Soot formation,number,mass,size and structure are all closely related to spray flame combustion process.

关 键 词：碳烟 定容燃烧弹 喷雾火焰 TEM 微观形貌 

分 类 号：TK411[动力工程及工程热物理—动力机械及工程]