喷射率对柴油机性能和排放影响数值模拟研究  

Numerical simulation research into effects of injection rates on performances and emissions of diesel engine

作　　者：冷先银[1] 隆武强[1] 冯立岩[1] 董全[1] 李海鹰[1] 王向军 余勇新 王爱国 

机构地区：[1]大连理工大学内燃机研究所,辽宁大连116024 [2]陕西柴油机重工有限公司,陕西兴平713100

出　　处：《大连理工大学学报》2011年第2期180-187,共8页Journal of Dalian University of Technology

基　　金：国家部委预先研究资助项目(A1420060212)

摘　　要：为了以较低的成本降低中速大功率船用柴油机的NOx排放,开发了一种可实现靴型燃油喷射规律的调压孔式喷油泵.利用三维CFD软件AVL FIRE v8.5对某大功率中速船用柴油机的缸内流动、混合气形成和燃烧过程进行了模拟计算,分析了调压孔式喷油泵的靴型喷射规律在2种负荷、3种喷油定时下对柴油机性能和排放的影响.结果表明:所用靴型喷射规律可以获得比原机更低的NOx排放,其中Boot1规律可以获得更好的φ(NOx)-φ(碳烟)折中关系,而Boot2规律可以获得更好的φ(NOx)-bi折中关系;确保靴型喷射规律的后期喷油率较高,有利于降低柴油机的碳烟排放和油耗.在一台6缸柴油机上进行了台架试验,证明了数值模拟预测结果的可信性.To reduce the NOx emissions from medium speed marine diesel engines with low costs,a pressure-modulating-hole type fuel pump was developed,which could provide boot-type injection rates.3D CFD package AVL FIRE v8.5 was used to simulate the in-cylinder gas flow,fuel-air mixing and combustion processes of a medium speed,high-power marine diesel engine.And the effects of the boot-type injection rates provided by the new pumps on the performance and emissions at 2 loads with 3 injection timings of the engine were analyzed.The simulation results indicate that,lower NOx emissions are obtained with the boot-type injection rates,among which the injection rate Boot1 can produce better φ（NOx）-φ（soot） compromise relationship,while injection rate Boot2 can produce better φ（NOx）-bi compromise relationship.Moreover,assuring the higher injection rates at the later stages of the boot-type injection is beneficial to reducing the soot emission and fuel consumption of the diesel engine.Bench tests were performed in a 6-cylinder diesel engine,and the results verify that the numerical simulation prediction is reliable.

关 键 词：柴油机 靴型喷油率 性能 排放 

分 类 号：TK421.2[动力工程及工程热物理—动力机械及工程]