喷嘴参数对柴油机喷油规律与性能的影响  

Impacts of nozzle parameters on diesel fuel injection pattern and performance

作　　者：李华莹[1] 刘建敏[1] 郭猛超[1] 

机构地区：[1]装甲兵工程学院机械工程系,北京100072

出　　处：《中国工程机械学报》2012年第2期242-247,共6页Chinese Journal of Construction Machinery

基　　金：军队科研计划资助项目(2009BZ50)

摘　　要：采用广安博之(Hiroyasu)等准维模型,建立高原运行柴油机工作过程模型;基于一维非定常可压缩理论建立柴油机喷射系统模型,二者耦合计算高原环境喷油器主要结构参数对柴油机实际运行时的喷油规律、燃烧特性和输出性能的影响.台架试验验证了模型的可信性.结果表明:喷孔数和喷孔直径对喷油规律影响最为敏感,喷孔夹角对喷油规律影响微弱.在海拔4 000m时,针对该型柴油机,喷孔面积存在一个最优区间,在该区间给出了功率变化率和喷孔面积的关系式.在燃烧室结构和供油系统参数不变的情况下,当喷孔面积减小为原喷孔的25%～60%时,柴油机功率最大提升8.5%;油耗最大下降8.8%,排气温度下降35℃以上.但是缸内温度明显上升,NOx排放恶化.研究为通过优化喷油器参数改善高原运行柴油机燃烧和性能提供了参考.By applying the ttiroyasu＇ s quasi-dimensional model, a plateau-operational process model is first established for diesel engines. Based on the one-dimensional non-steady compressible theory, the diesel injection system model is then constructed. With coupling of bespoke models, the pattern of major injector structural parameters upon actually-operational injection, together with combustion property and output performance, is calculated. Finally, the model feasibility is verified via bench testing. In this regard, it is detected from results that the nozzle-hole number and diameter are most sensitive to the fuel injection pattern, whereas the nozzle-cone angle is least sensitive to that pattern. With regard to 4 km altitude, an optimal interval, which presents a relational expression between power variance ratio and injection-hole area, exists for injection-hole area. Under the conditions of constant combustion chamber structure and fu- el-supply system parameters, while the injection-hole area is reduced by 60 % to 25 %, the diesel-engine power is utmost raised by 8.5 %, the fuel consumption is utmost reduced by 8.8 %, and the exhaust temperature is decreased by 35 ℃. Thus, the cylinder temperature is significantly increased, and the NOx emission is deteriorated. Therefore, this approach sets a reference to optimizing the injector parameters and improving the plateau-operational diesel-engine combustion and performance.

关 键 词：喷嘴 喷油规律 工作过程 

分 类 号：TK421.2[动力工程及工程热物理—动力机械及工程]