Investigation of the Effects of Injection Timing on Engine Performance and Formation of Emission in Homogeneous Charge Compression Ignition Engines

Öz

Homogeneous charge compression ignition engines are considered to be promising in studying areas due to their low NOx and soot emissions. Particularly, it is aimed to improve combustion by changing the injection strategies of diesel fuel. In this study, different spray timing for a homogeneous charge compression ignition engine was investigated under diesel engine conditions. Also, the AVL-FIRE numerical software was used in this study. Further, injection timing was examined at -150CA, -120CA, -90CA, -60CA and -30CA before the top dead center (BTDC). The injection was completed 5CA after TDC for all injection timings. The results showed that high temperatures, high NOx and soot emissions were obtained at early injection timing. Especially, lower NOx and soot emissions were obtained in the retarded injection timings such as -90KA and -60KA. However, in the case of late injection, CO emissions were increased.

Anahtar Kelimeler

• Homogeneous charge compression ignition (HCCI) engines,Injection timing

Homojen Dolgulu Sıkıştırma Ateşlemeli Motorlarda Enjeksiyon Zamanlamasının Motor Performansı ve Emisyon Oluşumuna Etkilerinin İncelenmesi

Öz

Homojen dolgulu sıkıştırma ateşlemeli motorlar düşük NOx ve is emisyonları sağlaması sebebiyle umut verici çalışma alanları olarak görülmektedir. Özellikle dizel yakıtının püskürtme stratejilerinin değiştirilmesiyle yanmanın iyileştirilmesi hedeflenmektedir. Bu çalışma kapsamında dizel motor şartları altında homojen dolgulu sıkıştırma ateşlemeli bir motor için krank açısına (KA) bağlı farklı püskürtme zamanlaması araştırılmıştır. Çalışma AVL-FIRE sayısal yazılımı kullanılarak gerçekleştirilmiştir. Enjeksiyon üst ölü noktadan (ÜÖN) önce sırasıyla -150KA, -120KA, -90KA, -60KA ve -30KA’nda başlayan zamanlamalar için incelenmiştir. Tüm püskürtme zamanlamaları için enjeksiyon ÜÖN’dan 5KA sonra tamamlanmıştır. Çalışmalar sonucunda erken enjeksiyon zamanlamalarında yüksek sıcaklıklar ve kısmen yüksek NOx ve is emisyonları elde edilmiştir. Özellikle -90KA ve -60KA gibi geciken enjeksiyon zamanlamalarında daha düşük NOx ve is emisyonları elde edilmiştir. Fakat enjeksiyonun daha geç yapılması durumunda ise CO emisyonlarının arttığı gözlenmiştir.

Anahtar Kelimeler

• Homojen dolgulu sıkıştırma ateşlemeli motorlar,Enjeksiyon zamanlaması,Yanma,Kirletici emisyonlar

Kaynakça

1. AVL-FIRE User Guide, 2013.
2. Coskun, G. Demir, U. Soyhan, H. S. Turkcan, A. Ozsezen A. N. and Canakci, M. 2018. “An experimental and modeling study to investigate effects of different injection parameters on a direct injection HCCI combustion fueled with ethanol–gasoline fuel blends”, Fuel , 215, 879–891.
3. Combustion Module, 2013. AVL FIRE user Manual v.2013. 2, 2013.
4. Dukowicz, J.K. 1997. Quasi-steady droplet change in the presence of convection. informal report Los Alamos Scientific Laboratory, LA7997-MS.
5. Emission Module, 2013. AVL FIRE user Manual v.2013. 2, 2013.
6. Fang, Q. Fang, J. Zhuang, J. and Huang, Z. 2012. “Influences of pilot injection and exhaust gas recirculation (EGR) on combustion and emissions in a HCCI-DI combustion engine”, Applied Thermal Engineering, 48, 97-104.
7. Jafarmadar, S. Nemati, P. and Khodaie, R. 2015. “Multidimensional modeling of the effect of Exhaust Gas Recirculation (EGR) on exergy terms in an HCCI engine fueled with a mixture of natural gas and diesel”, Energy Conversion and Management , 105, 498–508.
8. Khandal, S.V. Banapurmath, N.R. Gaitonde V.N. and Hiremath, S.S. 2017. “Paradigm shift from mechanical direct injection diesel engines to advanced injection strategies of diesel homogeneous charge compression ignition (HCCI) engines- A comprehensive review”, Renewable and Sustainable Energy Reviews, 70, 369–384.

9. Kozarac, D. Taritas, I. Vuilleumier, D. Saxena S. and Dibble, R. W. 2016. “Experimental and numerical analysis of the performance and exhaust gas emissions of a biogas/n-heptane fueled HCCI engine”, Energy, 115, 180-193.
10. Lapuerta, M. Hernandez, J.J. and Gimenez, F. 2000. “Evaluation of exhaust gas recirculation as a technique for reducing diesel engine NOx emissions”, Proc Inst Mech Eng Part D J Autom Eng, 214, 85–93.
11. Liu, A.B. Reitz, R.D. 1993. “Modeling the Effects of Drop Drag and Break-up on Fuel Sprays”. SAE 930072.
12. Mathivanan, K. Mallikarjuna J. M. and Ramesh A. 2016. “Influence of multiple fuel injection strategies on performance and combustion characteristics of a diesel fuelled HCCI engine – An experimental investigation”, Experimental Thermal and Fluid Science, 77, 337–346.
13. Naber, J.D. Reitz, R.D. 1988. “Modeling Engine Spray/Wall Impingement.” SAE-880107.
14. O'Rourke, P.J. 1989. “Statistical Properties and Numerical Implementation of a Model for Droplet Dispersion in Turbulent Gas” J. Comput. Physics 83, 1989.
15. Suzuki, H. Koike, N. Ishii H. and Odaka, M. 1997. “Exhaust purification of diesel engines by homogeneous charge with compression ignition part1: experimental investigation of combustion and exhaust emission behavior under pre-mixed homogeneous charge compression ignition method”, SAE Paper No. 970313.
16. Turkcan, A. Altinkurt, M. D. Coskun, G. and Canakci, M. 2018. “Numerical and experimental investigations of the effects of the second injection timing and alcohol-gasoline fuel blends on combustion and emissions of an HCCI-DI engine”, Fuel, 219, 50–61.
17. Yao, M.F. Zheng, Z.L. and Liu, H.F. 2009 “Progress and recent trends in homogeneous charge compression ignition (HCCI) engines”, Prog. Energ. Combust. Sci., 35, 398-437.
18. Yousefzadeh, A. and Jahanian, O. 2017. “Using detailed chemical kinetics 3D-CFD model to investigate combustion phase of a CNG-HCCI engine according to control strategy requirements”, Energy Conversion and Management , 133, 524–534.
19. Zheng, M. Reader, G.T. and Hawley, J.G. 2004. “Diesel engine exhaust gas recirculation – a review on advanced and novel concepts”. Energy Convers Manage, 45, 883–900.