高海拔共轨柴油机煤基复合燃料排放的数值模拟
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摘要
为分析煤基复合燃料对共轨柴油机高海拔碳烟和NOx排放的影响,基于AVL FIRE数值分析软件,建立煤基复合燃料柴油机高海拔燃烧过程仿真模型并进行试验验证。探究煤基复合燃料柴油机高海拔缸内物理场变化规律和碳烟(Soot)与NOx形成历程。结果表明:随着海拔的升高,煤基复合燃料柴油机缸内气流运动速度最大值减小,最高燃烧温度和燃空当量比增大,NO质量分数减少,但Soot质量分数增多且最大值对应曲轴转角增大。与海拔3 500 m相比,海拔5 500 m煤基复合燃料柴油机燃烧后期NO减少69.8%,Soot增多18.6倍。与燃用柴油相比,煤基复合燃料柴油机燃空当量比降低,NO增多,Soot减少,且海拔越高Soot减少幅度越大,海拔5 500 m时Soot减少83.1%。
To analyze the influence of coal-based composite fuel on the soot and NOx emitted by a diesel engine operating at high altitude, the paper applies AVL FIRE numerical analysis software to simulate the combustion process of the engine,and studies the change of in-cylinder physical field as well as the generation of soot and NOx. Experimental results show that with the elevation of altitude, although the maximal speed of in-cylinder air flow and NO mass fraction would decrease, the maximal combustion temperature and fuel-air equivalence ratio increase as well as the maximum corresponding to the craft angle. At the end of combustion, an engine working at an altitude of 5 500 meters would decrease NO by 69.8 percent while increase soot by 18.6 times more than that at 3 500 meters. Compared to a diesel engine, the engine using coal-based fuel has a lower fuel-air equivalence ratio, more NO emission and less soot. The higher the altitude, the quickly loot would decrease with on 83.1 percent reduction at the altitude of 5 500 meters.
To analyze the influence of coal-based composite fuel on the soot and NOx emitted by a diesel engine operating at high altitude, the paper applies AVL FIRE numerical analysis software to simulate the combustion process of the engine,and studies the change of in-cylinder physical field as well as the generation of soot and NOx. Experimental results show that with the elevation of altitude, although the maximal speed of in-cylinder air flow and NO mass fraction would decrease, the maximal combustion temperature and fuel-air equivalence ratio increase as well as the maximum corresponding to the craft angle. At the end of combustion, an engine working at an altitude of 5 500 meters would decrease NO by 69.8 percent while increase soot by 18.6 times more than that at 3 500 meters. Compared to a diesel engine, the engine using coal-based fuel has a lower fuel-air equivalence ratio, more NO emission and less soot. The higher the altitude, the quickly loot would decrease with on 83.1 percent reduction at the altitude of 5 500 meters.
引文
[1]刘瑞林.柴油机高原环境适应性研究[M].北京:北京理工大学出版社,2013:77-126.
[2] HE C,GE Y,MA C,et al. Emission characteristics of a heavy-duty diesel engine at simulated high altitudes[J]. Science of the Total Environment,2011,409(17):3138-3143.
[3]国家环境保护部.轻型汽车污染物排放限值及测量方法(中国六阶段):GB 18352.6—2016[S].北京:中国环境出版社,2016.
[4] BENJUMEA P,AGUDELO J,AGUDELO A. Effect of altitude and palm oil biodiesel fuelling on the performance and combustion char-acteristics of a HSDI diesel engine[J]. Fuel,2009,15(4):725-731.
[5] DOBRZINSKIJ N.A theoretical study of military fuel combustion rate in diesel engines under high-altitude conditions[J].Fuel,2012,18(6):734-738.
[6] LI G L,LAI C J,SUN W C,et al. Effect of biodiesel fuel on particle size distribution in diesel engine emission during cruise cycles[J]. Journal of Thermal Science and Technology,2011,10(3):264-268.
[7] GRABOSKI M S,MCCORMICK R L. Effect of diesel fuel chem-istry on regulated emissions at high altitude[C]. SAE Technical Paper 1996-961947.
[8]申立中,杨永忠,雷基林,等.不同海拔下增压中冷柴油机性能和排放的研究[J].内燃机学报,2006,24(3):250-255.
[9]董素荣,刘瑞林,周广猛,等.煤基复合燃料柴油机不同海拔燃烧与排放特性[J].工程热物理学报,2018(5):1161-1167.
[2] HE C,GE Y,MA C,et al. Emission characteristics of a heavy-duty diesel engine at simulated high altitudes[J]. Science of the Total Environment,2011,409(17):3138-3143.
[3]国家环境保护部.轻型汽车污染物排放限值及测量方法(中国六阶段):GB 18352.6—2016[S].北京:中国环境出版社,2016.
[4] BENJUMEA P,AGUDELO J,AGUDELO A. Effect of altitude and palm oil biodiesel fuelling on the performance and combustion char-acteristics of a HSDI diesel engine[J]. Fuel,2009,15(4):725-731.
[5] DOBRZINSKIJ N.A theoretical study of military fuel combustion rate in diesel engines under high-altitude conditions[J].Fuel,2012,18(6):734-738.
[6] LI G L,LAI C J,SUN W C,et al. Effect of biodiesel fuel on particle size distribution in diesel engine emission during cruise cycles[J]. Journal of Thermal Science and Technology,2011,10(3):264-268.
[7] GRABOSKI M S,MCCORMICK R L. Effect of diesel fuel chem-istry on regulated emissions at high altitude[C]. SAE Technical Paper 1996-961947.
[8]申立中,杨永忠,雷基林,等.不同海拔下增压中冷柴油机性能和排放的研究[J].内燃机学报,2006,24(3):250-255.
[9]董素荣,刘瑞林,周广猛,等.煤基复合燃料柴油机不同海拔燃烧与排放特性[J].工程热物理学报,2018(5):1161-1167.