Hava Fazlalık Katsayısı ve Oktan Sayısı Değişiminin HCCI Yanma Karakteristiklerine ve Motor Performansına Etkileri

Yıl 2019, Cilt: 22 Sayı: 3, 607 - 618, 01.09.2019

Alper Calam , Yakup İçingür

https://doi.org/10.2339/politeknik.444377

Cited By: 5

Öz

Homojen dolgulu sıkıştırma ile ateşlemeli
(HCCI) motorlar yüksek termik verimleri ve düşük egzoz emisyonları nedeniyle
mevcut içten yanmalı motorlara alternatif bir yanma modelidir. Bu çalışmada, port tipi
enjeksiyonlu, tek silindirli bir HCCI motorda hava fazlalık katsayısının ve
oktan sayısının HCCI yanması üzerine etkileri deneysel olarak incelenmiştir.
Deneyler tam yük şartlarında, 60 ^oC emme havası giriş sıcaklığında
ve 800 min^-1 motor hızında yapılmıştır. Ayrıca deneyler farklı hava
fazlalık katsayılarında yapılmıştır. Oktan sayısının artırılması ile maksimum
silindir içi basıncın oluşum noktası daha geç krank açılarında gerçekleşmiştir.
Oktan sayısının artırılması yanma süresinin uzamasına neden olmuştur. Hava/
yakıt oranının artması basınç artış oranını azaltmıştır. Hava/yakıt oranının
azaltılması silindir içerisine sürülen enerji miktarını artırmıştır. Böylece en
yüksek silindir içi basınçlar bu şartlar altında elde edilmiştir. En yüksek
indike termik verim RON60 yakıtı kullanımında, hava yakıt oranının 2,14 olduğu
şartlarda % 40,6 olarak tespit edilmiştir. Hava yakıt oranının azaltılması
yanmanın erken gerçekleşmesini sağlamıştır. Bu nedenle net iş azalmıştır.
Böylece indike termik verim de azalmıştır.

Anahtar Kelimeler

Hava yakıt oranı, HCCI, yanma, RON20, RON60, egzoz emisyonları

The Effects of Air Fuel Ratio and Octane Number on HCCI Combustion and Engine Performance Characteristics

Öz

Homogeneous compression ignition (HCCI) engines are an alternative
combustion model to existing internal combustion engines due to their high
thermal efficiency and low exhaust emissions. In this study, the effects of air
fuel ratio and octane number on combustion and engine performance
characteristics were investigated with port type injection single cylinder HCCI
engine. Experiments were carried out at full load conditions, intake
temperature of 60 ^oC and 800 rpm engine speed. Also, experiments
were carried out with different air excess coefficients. The maximum
in-cylinder pressure occured at a later crank angle by increasing the number of
octane. Increasing the octane number has caused the increase of the combustion
duration. The increase of air fuel ratio decreases the pressure rise rate.
Decreases of air fuel ratio has increased the amount of injected energy to the
cylinder. So that, the highest in-cylinder pressures are obtained under these
conditions. The highest indictical thermal efficiency 40.6 %, provided that the
air fuel ratio was 2.14 with using RON60 fuel. Decreases of air fuel ratio
caused the combustion advance. For this reason net work decreased. Thereby,
indicated thermal efficiency decreased.

Anahtar Kelimeler

Air fuel ratio, HCCI, combustion, RON20, RON60, exhaust emissions

Kaynakça

• [1] Mohanamurugan S., Sendilvelan S. "Emission and combustion characteristics of different fuel In A HCCI engine", International Journal of Automotive and Mechanical Engineering, 3:279–292, (2011).
• [2] Hairuddin A., Wandel A., Yusaf T. "An introduction to a homogeneous charge compression ignition engine", The Journal of Mechanical Engineering Science, 7:1042–1052, (2014).
• [3] Hasan M.M., Rahman M.M., Kadirgama K.. "A review on homogeneous charge compression ignition engine performance using biodiesel-diesel blend as a fuel", International Journal of Automotive and Mechanical Engineering, 11:2199–2211, (2015).
• [4] Machrafi H., Cavadiasa S. "An experimental and numerical analysis of the influence of the inlet temperature, equivalence ratio and compression ratio on the HCCI auto-ignition process of Primary Reference Fuels in an engine" Fuel Processing Technology, 89: 1218-1226, (2008).
• [5] Polovina D., McKenna D., Wheeler J., Sterniak J., Miersch-Wiemers O., Mond A. "Steady-state combustion development of a downsized multi-cylinder engine with range extended HCCI/SACI capability", SAE Technical Paper, 2013-01-1655, (2013).
• [6] Najafabadi M.I., Abdul A.N. "Homogeneous charge compression ignition combustion: challenges and proposed solutions", Journal of Combustion, Article ID783789, 14pages, (2013)
• [7] Yao M., Zheng Z., Liu H. "Progress and recent trends in homogeneous charge compression ignition (HCCI) engines", Progress in Energy and Combustion Science, 35: 398–437, (2009).
• [8] Saxena S., Bedoya I.D. "Fundamental phenomena affecting low temperature combustion and HCCI engines, high load limits and strategies for extending these limits", Progress in Energy and Combustion Science, 39: 457–488, (2013).
• [9] Zheng J., Yang W., Miller D.L., Cernansky N.P. "A skeletal chemical kinetic model for the HCCI combustion process", SAE Technical Paper,2002-01-0423, (2002).
• [10] Christensen M., Johansson B. "Influence of mixture quality on homogenous charge compression ignition", SAE Technical Paper, 2000-01-2454, (2000).
• [11] Yang J., Kenney T. "Some concept of DISI engine for high fuel efficiency and low emissions", SAE Technical Paper, 2002-01-2747, (2002).
• [12] Yang J., Culp T., Kenney T. "Development of a gasoline engine system using HCCI technology-the concept and the test results", SAE Technical Paper, 2002-01-2832, (2002).
• [13] Maurya R.K., Agarwal A.K. "Experimental study of combustion and emission characteristics of ethanol fuelled port injected homogenous charge compression ignition (HCCI) combustion engine", Applied Energy, 88: 1169-1180 (2011).
• [14] Lu X., Hou Y., Zu L., Huang Z. "Experimental study on the auto ignition and combustion characteristics in the homogeneous charge compression ignition (HCCI) combustion operation with ethanol/n-heptane blend fuel by port injection", Fuel, 85: 2622-2631, (2006).
• [15] Uyumaz A., Solmaz H., Yılmaz E., Yamık H., Polat S. "Experimental examination of the effects of military aviation fuel JP-8 and biodiesel fuel blends on the engine performance, exhaust emissions and combustion in a direct injection engine", Fuel Processing Technology, 128: 158–165, (2014).
• [16] Dec J.E. "Advanced compression–ignition engines-understanding the incylinder processes", Proceedings of the Combustion Institute, 32: 2727–2742, (2009).
• [17] Imtenan S., Varman M., Masjuki H.H., Kalam M.A., Sajjad H., Arbab M.I. "Impact of low temperature combustion attaining strategies on diesel engine emissions for diesel and biodiesels: a review", Energy Conversion and Management, 80: 329–356, (2014).
• [18] Cinar C., Uyumaz A., Solmaz H., Sahin F., Polat S., Yilmaz E. "Effects of intake air temperature on combustion, performance and emission characteristics of a HCCI engine fueled with the blends of 20% n-heptane and 80% isooctane fuels", Fuel Processing Technology, 130: 275–281, (2015).
• [19] Curran H.J., Gaffuri P., Pitz J.W., Westbrook C.K. "A comprehensive modeling study of n-heptane oxidation", Combustion and Flame, 114: 149–177, (1998).
• [20] Saisirirat P., Togbe C., Chanchaona S., Foucher F., Mounaim-Rousselle C., Dagaut P. "Auto-ignition and combustion characteristics in HCCI and JSR using 1-butanol/ n-heptane and ethanol/n-heptane blends", Proceedings of the Combustion Institute, 33: 3007–3014, (2011).
• [21] Yao M., Zheng Z., Zhang B., Chen Z. "The effect of PRF fuel octane number on HCCI opeation", SAE Technical Paper, 2004-01-2292, (2004).
• [22] He B.Q., Liu M.B., Yuan J., Zhao H. "Combustion and emission characteristics of a HCCI engine fuelled with n-butanol-gasoline blends", Fuel, 108: 668-674 (2013).
• [23] Hyvonen J., Haraldsson G., Johansson B. "Operating conditions using spark assisted CCI combustion during combustion mode transfer to SI in a multicylinder VCR-HCCI engine", SAE Technical Paper, 2005-01-0109, (2005).
• [24] Wagner R., Edwards K., Daw C., Green J., Bunting B. "On the nature of cyclic dispersion in spark assisted HCCI combustion", SAE Technical Paper, 2006-01-0418, (2006)
• [25] Wang Z., Wang J.X., Shuai S.J., Ma Q.J. "Effects of spark ignition and stratified charge on gasoline HCCI combustion with direct injection", SAE Technical Paper, 2005-01-0137, (2005)
• [26] Zhao H. "CCI and CAI Engines For The Automotive Industry", England: Woodhead Publishing Limited, (2007).
• [27] Sudheesh K., Mallikarjuna J.M. "Diethyl ether as an ignition improver for biogas homogeneous charge compression ignition (HCCI) operation-An experimental investigation", Energy, 35(9): 3614-3622, (2010).
• [28] Ma J., Lü X., Ji L., Huang Z. "An experimental study of HCCI-DI combustion and emissions in a diesel engine with dual fuel", International Journal of Thermal Sciences, 47(9): 1235-1242, (2008).
• [29] Polat S. "An experimental study on combustion, engine performance and exhaust emissions in a HCCI engine fuelled with diethyl ether–ethanol fuel blends." Fuel Processing Technology, 143: 140-150, (2016).
• [30] Wallner T., Miers S.A., McConnell S. "A comparison of ethanol and butanol as oxygenates using a direct-injection, spark-ignition engine", Journal of Engineering for Gas Turbines and Power, 131(3): 032802, (2009).
• [31] Christensen M., Hultqvist A., Johansson B. "Demonstrating the multi fuel capability of a homogeneous charge compression ignition engine with variable compression atio", SAE Technical Paper, 1999-01-3679, (1999).
• [32] Kim M.Y., Lee C.S. "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(17-18): 2871-2880, (2007).
• [33] Guo H., Neill W.S., Chippior W., Li H., Taylor J.D. "An experimental and modeling study of HCCI combustion using n-heptane", Journal of Engineering for Gas Turbines and Power, 132(2): 022801, (2010).
• [34] Iida M., Hayashi M., Foster D.E., Martin J.K. "Characteristics of homogeneous charge compression ignition (HCCI) engine operation for variations in compression ratio, speed, and intake temperature while using n-butane as a fuel", Journal of engineering for gas turbines and power, 125(2): 472-478, (2003).