ÇOK PÜSKÜRTMELİ DİREKT ENJEKSİYONLU DİZEL BİR MOTORDA ENJEKSİYON STRATEJİLERİNİN YANMA KARAKTERİSTİKLERİ VE KİRLETİCİ EMİSYONLAR ÜZERİNDEKİ ETKİLERİNİN ANALİZİ

Year 2019, Volume: 39 Issue: 1, 1 - 15, 30.04.2019

Müjdat Fırat Yasin Varol

Abstract

Direk enjeksiyonlu dizel bir motorda çok püskürtmeli yakıt enjeksiyonu ve farklı püskürtme açılarının yanma karakteristikleri ve emisyon oluşumuna etkilerini açıklamak amacıyla gelişmiş HAD simülasyonu gerçekleştirilmiştir. AVL-FIRE yazılımı kullanılarak silindir içi basınç, sıcaklık, ısı salınım oranı, yanma süreci ve emisyon oluşumları farklı püskürtme açıklarında gösterilmiştir. Yanma modeli olarak gelişmiş ECFM-3Z model kullanılmış olup, NO ve İs oluşumları için sırasıyla gelişmiş Zeldovich ve Kinetik modeller kullanılmıştır. Sayısal simülasyonlar, silindir içi basınç ve ısı salınım oranına bağlı deneysel verilerle doğrulandıktan sonra, püskürtme açısının etkisinin incelenmesi için geliştirilmiştir. Sayısal çalışmalarla silindir içi basınç ve ısı salınım oranının 120º ve 160º püskürtme açılarında kısmen artığı gözlenmiştir. Kütlesel NO oranı 150º püskürtme açısında en düşük olarak elde edilirken, kütlesel İs oranı 120º ve 160º püskürtme açılarında en düşük sonucu vermiştir. Tüm simülasyon konfigürasyonları yanma stroku boyunca silindir içi etkileri anlamak için gerçekleştirilmiştir. Elde edilen sonuçlar yanma sürecini etkileyecek ve yeni nesil emisyonları tamamen değiştirecek kadar önemlidir.

Keywords

Çoklu püskürtme, Dizel yanması, Kirletici Emisyonlar, HAD simülasyonu

ANALYSIS THE EFFECTS OF INJECTION STRATEGIES ON COMBUSTION CHARACTERISTICS AND POLLUTANT EMISSIONS IN A MULTIPLE DIRECT INJECTION DIESEL ENGINE

Abstract

An advanced CFD simulation has been performed to explore different spray cone angles and multiple-fuel injection on combustion characteristics and emission formations in a DI-diesel engine. The in-cylinder pressure, temperature, heat release rate, combustion progresses and formation of emissions are simulated at different spray cone angles with AVL-FIRE code. An improved version of the ECFM-3Z combustion model has been applied and coupled with advanced Zeldovich and Kinetic models for NO and soot formation, respectively. After the validation of cylinder pressure and heat release rate experimental engine tests, further numerical simulations were performed to investigate the effects of spray cone angles. It has been determined that the cylinder peak pressure and heat release rate were slightly increased by 120° and 160° spray cone angles. The NO mass fraction is the lowest at a spray angle of 150°, while the soot mass fraction is the lowest at spray cone angles of 120° and 160°. Simulations of all configurations were subsequently performed to understand the effects of in-cylinder parameters during the combustion stroke. These results are significant enough to affect the combustion process and completely change the next generation of emissions.

Keywords

Multiple injections, Diesel combustion, Pollutant emissions, CFD simulation

References

• Combustion Module, 2013. AVL FIRE user Manual v.2013. 2, 2013.
• Desantes J.M., Payri R., Garcia A., Manin J., 2009, Experimental study of biodiesel blends effects on diesel injection processes, Energy Fuel, 23, 3227-3235
• Dukowicz J.K., 1979, Quasi-steady droplet change in the presence of convection. informal report Los Alamos Scientific Laboratory, LA7997-MS.
• Emission Module, 2013. AVL FIRE user Manual v.2013. 2, 2013.
• Firat M., Investigation of spray dynamics and combustion on different combustion chambers and spray models in internal combustion engines. PhD Thesis, Firat University, Inst. Science Graduate School Natural Applied Sciences, 2014
• Firat M., 2013, Numerical Investigation of Heat Transfer, Fluid Flow and Formation of Emissions in Diesel Engines, Proc ASME 2013 Int Mech Eng Cong Expo (IMECE2013), San Diego, California; 2013:64107.
• Ganippa L.C., Andersson S., Chomiak J., Matsson A., Combustion characteristics of diesel sprays from equivalent nozzles with sharp and rounded inlet geometries, Combust. Sci. and Tech., 175, 1015-1032,.
• Gonzalez M., Lian Z., Reitz R.D., 1992, Modeling Diesel Engine Spray Vaporization and Combustion, SAE paper 920579.
• Gosman A.D., Ioannides E., 1981, Aspects of Computer Simulation of Liquid- Fueled Combustors, AIAA, 81-323.
• Jaichandar S., Annamalai K., 2013, Combined impact of injection pressure and combustion chamber geometry on the performance of a biodiesel fueled diesel engine, Energy, 55, 330-339.
• Kim M.Y., Lee C.S., 2007, Effect of a narrow fuel spray angle and a dual injection configuration on the improvement of exhaust emissions in a HCCI diesel engine, Fuel, 86, 2871–2880.
• Li X., Sun Z., Du W., Wei R., 2010, Research and Development of Double Swirl Combustion System for a DI Diesel Engine, Combust. Sci. and Tech., 182: 1029–1049,.
• Liu A.B., Mather D., Reitz R.D., 1993, Modeling the Effects of Drop Drag and Breakup on Fuel Sprays, SAE paper 930072.
• Liu A.B., Reitz, R.D., 1993, Modeling the Effects of Drop Drag and Break-up on Fuel Sprays, SAE 930072.
• Mobasheri R., Peng Z., Mirsalim S.M., 2012, Analysis the effect of advanced injection strategies on engine performance and pollutant emissions in a heavy duty DI-diesel engine by CFD modeling, Int. J. Heat Fluid Flow,33, 59–69.
• Naber J.D., Reitz R.D., 1988, Modeling Engine Spray/Wall Impingement. SAE-880107. O'Rourke P.J., 1989, Statistical Properties and Numerical Implementation of a Model for Droplet Dispersion in Turbulent Gas. J. Comput. Physics 83, 1989.
• Petranovic Z., Besenic T., Vujanovic M., Duic N., 2017, Modelling pollutant emissions in diesel engines, influence of biofuel on pollutant formation, J. Environmental Management, 203, 1038-1046.
• Prasad B.V.V.S.U., Sharma C.S., Anand T.N.C, Ravikrishna RV., 2011, High swirl-inducing piston bowls in small diesel engines for emission reduction, Applied Energy, 88, 2355–2367.
• Petranović Z., Sjerić M., Taritaš I., Vujanović M., Kozarac D., 2018, Study of advanced engine operating strategies on a turbocharged diesel engine by using coupled numerical approaches, Energy Conversion and Management, 171, 1–11.
• Reitz R.D., Diwakar J., 1986, Effect of Drop Break-up on Fuel Sprays. 1986; SAE Technical Papers Series, 860469.
• Soid S.N., Zainal Z.A., 2011, Spray and combustion characterization for internal combustion engines using optical measuring techniques-A review, Energy, 36, 724-741.
• Su L.W., Li X.R., Zhang Z., Liu F.S., 2014, Numerical analysis on the combustion and emission characteristics of forced swirl combustion system for DI diesel engines, Energy Conversion and Management, 86, 20–27.
• Varol Y., Oztop H.F., Firat M., Koca A., 2010, CFD modeling of heat transfer and fluid flow inside a pent-roof type combustion chamber using dynamic model, Int. Comm. Heat Mass Transfer,37, 1366–1375.
• Wei S., Ji K., Leng X., Wang F., Liu X., 2014, Numerical simulation on effects of spray angle in a swirl chamber combustion system of DI (direct injection) diesel engines, Energy, 75, 289-294.
• Xin J., Ricart L., Reitz R.D., 1998, Computer Modeling of Diesel Spray Atomization and Combustion, Combust. Sci. and Tech., 137, 171-194
• Yadollahi B., Boroomand M., 2013, The effect of combustion chamber geometry on injection and mixture preparation in a CNG direct injection SI engine, Fuel,107, 52-62.
• Yu L., Ge Y., Tan J., He C., Wang X., Liu H., Zhao W., Guo j., Fu G., Feng X., Wang X., 2014, Experimental investigation of the impact of biodiesel on the combustion and emission characteristics of a heavy duty diesel engine at various altitudes, Fuel, 115,220–226.