适用于柴油HCCI燃烧的碳烟半经验模型研究  

A Phenomenological Soot Model for Diesel HCCI Combustion

作　　者：贾明[1] 彭志军 解茂昭[1] 周磊[1] 

机构地区：[1]大连理工大学能源与动力学院,辽宁大连116024 [2]Sussex大学工程与设计系

出　　处：《内燃机学报》2010年第1期33-41,共9页Transactions of Csice

基　　金：国家基础研究重点规划项目子课题(2007CB210002);国家自然科学基金项目(50806008)

摘　　要：将改进的碳烟半经验模型和简化正庚烷的化学反应机理纳入KIVA-3V程序中,以描述柴油燃烧过程中碳烟的生成和氧化历程。通过以正庚烷为燃料的激波管试验验证发现,在较宽的温度和压力范围内,该碳烟半经验模型可以相对准确地预测碳烟的生成率、颗粒直径和数密度。在定容燃烧器中典型的传统柴油机的扩散燃烧和接近于均质压燃(HCCI)发动机的预混燃烧状况下,应用此碳烟模型进一步研究了喷孔直径和喷射压力对碳烟排放的影响。结果发现模型预测得到的碳烟体积分数分布与试验吻合得较好,同时显示当控制局部当量比小于2.0时可以避免碳烟的生成。An improved phenomenological soot model coupled with a reduced n-heptane chemical mechanism was implemented into KIVA-3V code to describe soot formation and oxidation processes in diesel combustion. This model was validated by the shock-tube experiments with rich n-heptane mixture over a wide range of temperature and pressure. The computational results demonstrate that the phenomenological soot model is capable of predicting soot yield, particle diameter and number density with satisfactory accuracy. The model was further applied to investigate the influence of orifice diameter and injection pressure on soot emissions in a constant-volume combustion vessel under the conditions related to diffusion combustion in typical diesel engines and premixed combustion in homogeneous charge compression ignition （HCCI） engines. The predictions show qualitative agreement with the measurements on soot volume fraction distribution. The results also indicate that soot formation can almost be suppressed as the local equivalence ratio is less than 2.0.

关 键 词：均质压燃(HCCI) 柴油发动机 多维模型 碳烟模型 

分 类 号：TK401[动力工程及工程热物理—动力机械及工程]