GİRİŞ HAVASI SICAKLIĞININ HCCI MOTORUN YANMA VE PERFORMANSINA ETKİLERİ

Homojen dolgulu sıkıştırma ile ateşlemeli motorların endüstriyel olarak kullanılabilmesi için yüksek yüklerde oluşan vuruntu problemi ve düşük yüklerde oluşan ateşlenememe probleminin giderilmesi gerekmektedir. Bu çalışmada, port tipi enjeksiyonlu, tek silindirli bir HCCI motorda hava/yakıt oranının ve emme havası giriş sıcaklığının, RON20 yakıtı kullanımında HCCI yanması üzerine etkileri deneysel olarak incelenmiştir. HCCI motorun çalışma aralığını belirleyebilmek için 40 ̊C, 60 ̊C, 80 ̊C ve 100 ̊C emme havası giriş sıcaklıklarında ve RON20 deney yakıtı kullanılarak farklı hava fazlalık katsayılarında deneyler gerçekleştirilmiştir. Emme havası giriş sıcaklıklarının artmasıyla motorun çalışma aralığının genişleyerek daha fakir karışımlarda HCCI yanmasının sağlandığı görülmüştür. Sonuçlar emme havası giriş sıcaklığının artmasıyla silindir basıncının ve ısı yayılım oranının arttığını göstermiştir. Ayrıca emme havası giriş sıcaklığındaki artış yanma süresinin kısalmasına sebep olmuş ve maksimum silindir içi basıncın daha erken bir krank açısında oluştuğu görülmüştür. Maksimum silindir içi basıncın üst ölü noktadan önce gerçekleşmesi indike termik verimin bir miktar düşmesine sebep olmuştur. Emme havası giriş sıcaklığının artmasıyla çalışma aralığı daralmış ve silindire alınan havanın yoğunluğunun düşmesi sebebiyle oksijen miktarı da azalmış ve indike ortalama efektif basıncın azalmasına sebep olmuştur. Emme havası giriş sıcaklığının artırılması silindir içi moleküllerin hızını artırımış ve yanma iyileşmiştir. Bu sebeple HC ve CO emisyonları azalma eğilimi göstermektedir. Emme havası giriş sıcaklığının artması yanma sonu sıcaklıklarının da artmasına neden olmaktadır. Bu sebeple NOx emisyonları da artış göstermektedir.

Anahtar Kelimeler:

Alternatif motorlar, Yanma, Motor performansı, Yakıt, HCCI, Düşük sıcaklık yanması

EFFECTS OF INTAKE AIR TEMPERATURE ON COMBUSTION AND PERFORMANCE OF A HCCI ENGINE

In order to be able to use homogeneous charged compression ignition engines industrially, it is necessary to solve the problems of it such as misfiring at low loads and knocking at high loads. In this study, the effects of the intake air temperature and air/fuel ratio on combustion characteristics of a port type single cylinder HCCI engine were examined experimentally by using RON20 fuel. Experiments were carried out at intake temperatures of 40 ̊C, 60 ̊C, 80 ̊C and 100 ̊C and different air excess coefficients using RON20 test fuel to determine the operating range of the HCCI engine. It was seen that the operating range of the HCCI engine was extended and HCCI combustion was obtained with more lean mixtures. The results showed that the cylinder pressure and hear release rate were increased with the increase of intake air temperature. Furthermore, the increase of the intake air temperature caused the combustion duration to shorten and the location of the maximum cylinder pressure was advanced. The occurrence of the maximum cylinder pressure prior to top death center caused a decrease in thermal efficiency. Operating range expanded by increasing intake air temperature, however, due to decrease in the density of air taken into the cylinder, the amount of the oxygen had also decreased and it was lead to decrease in indicated mean effective pressure. Increasing the intake air inlet temperature increases the velocity of the molecules and improves the combustion. So that HC and CO emissions tend to decrease. Increasing the intake air temperature causes the temperature of the combustion of increase. Therefore, NOx emissions also increase. Keywords: Alternative engines,

Keywords:

Alternative engines, Combustion, Engine performance, Fuel, HCCI, Low temperature combustion,

PDF

___

A report to the US Congress, 2001, Homogeneous charge compression ignition (HCCI) technology., Energy Efficiency and Reneweable Energy Office of Transportation Technologies, U.S. Department of Energy.
Anonymous, 2005, 2,2,4-2-2-4 Trimethylpentane-compound summary, PubChem Compound. USA: National Center for Biotechnology Information 26 March Identification and Related Records, (Retrieved March 2012).
Baumgarter C., 2009, Mixture formation in internal combustion engines, Springer, Heat and Mass transfer series, Berlin, 253-278. Christensen M., Johansson B., 2000, Influence of mixture quality on homogenous charge compression ignition. SAE Technical Paper, 2000-01-2454.
Çınar C., Uyumaz, A., Solmaz H., Şahin F., Polat S., Yılmaz E., 2015, 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 Technologies, 130: 275-281.
Çınar C., Uyumaz, A., Solmaz H., Tolgül T., 2015, Effects of valve lift on the combustion and emissions of a HCCI gasoline engine. Energy Conversion and Management, 94: 159-168.
Çınar C., Uyumaz, A., Polat S., Yılmaz E., Can Ö., Solmaz H., 2016, Combustion and performance characteristics of an HCCI engine utilizing trapped residual gas via reduced valve lift. Applied Thermal Engineering, 100: 586-594.
Hatim M., 2008, Experimental validation of a kinetic multi-component mechanism in a wide HCCI engine operating range for mixtures of n-heptane, iso-octane and toluene: Influence of EGR parameters. Energy Conversion and Management, 49: 2956-2965.
He B.Q., Liu M.B., Yuan J., Zhao H., 2013, Combustion and emission characteristics of a HCCI engine fuelled with n-butanol-gasoline blends. Fuel, 108: 668-674.
Heywood, J.B., 1998, Internal combustion engines fundamentals (First edition). New York: McGraw-Hill, 503,506.
Hwang W., Dec J., Sjöberg M., 2008, Spectroscopic and chemical-kinetic analysis of the phases of HCCI autoignition and combustion for single- and two-stage ignition fuels. Combustion and Flame, 154: 387-409.
Imtenan S., Varman M., Masjuki H.H., Kalam M.A., Sajjad H., Arbab M.I., 2014, Impact of low temperature combustion attaining strategies on diesel engine emissions for diesel and biodiesels: a review. Energy Conversion and Management, 80: 329–356.
Kaiser E.W., Yang J., Culp T., Xu N., Maricq M.M., 2002, Homogeneous charge compression ignition engine -out emissions- does flame propagation occur in homogeneous compression ignition. International Journal of Engine Research 3, 185-195.
Li G., Zhang C., Zhou J., 2017, Study on the knock tendency and cyclical variations of a HCCI engine fueled with n-buthanol/n-heptane blends, Enegy Conversion and Management, 133: 548-557
Lu X., Hou Y., Zu L., Huang Z., 2006, 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.
Maurya, R.K., Agarwal, A.K., 2011, Experimental Investigation On The Effect Of Intake Air Temperature and Air–Fuel Ratio On Cycle-To-Cycle Variations Of HCCI Combustion and Performance Parameters. Applied Energy, 88: 1153-1163.
Maurya, R.K., Agarwal, A.K., 2011, Experimental study of combustion and emission characteristics of ethanol fuelled port injected homogenous charge compression ignition (HCCI) combustion engine, Applied Energy, 88: 1169-1180.
Miguel T.G., Francisco J.J.A., Tomas S.L., 2009, Experimental study of the performances of a modified diesel engine operating in homogeneous charge compression ignition (HCCI) combustion mode versus the original diesel combustion mode. Energy, 34: 159-171.
Natarajan S., Kumar M.A., Sundareswaran A.U.M., 2017, Computational analysis of an early direct injected HCCI engine using bio ethanol and diesel blends as fuel. Energy Procedia, 350-357.
Nathan S.S., Mallikarjuna J.M., Ramesh A., 2010, Effects of charge temperature and exhaust gas re-circulation on combustion and emission characteristics of an acetylene fuelled HCCI engine. Fuel, 89(2): 515-521.
Onishi S., Jo S.H., Shoda K., Jo P.D., Kato S., 1979, Active thermo-atmosphere combustion (ATAC) – a new combustion process for internal combustion engines. SAE paper No. 790501.
Persson H., Agrell M., Olsson J.O., Johansson B., Ström H., 2004, The effect of intake temperature on HCCI operation using negative valve overlap. SAE paper no: 010944.
Putrasari Y., Jamsran N., Lim O., 2017, An investigation DME HCCI autoignition unter EGR and boosted operation. Fuel, 200: 447-457.
Saisirirat P., Togbe C., Chanchaona S., Foucher F., Mounaim-Rousselle C., Dagaut P., 2011, 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.
Saxena S., Bedoya I.D., 2013, 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.
Seref S., 2005, Examination of combustion characteristics and phasing strategies of a natural gas HCCI engine. Energy Conversion and Management, 46: 101-119.
Uyumaz A., Solmaz H., Yılmaz E., Yamık H., Polat S., 2014, 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.
Yang J., Culp T., Kenney T., 2002, Development of a gasoline engine system using HCCI technology．The concept and the teat results [J]．SAE Paper No. 012832.
Yang J., Kenney T., 2002, Some concept of DISI engine for high fuel efficiency and low emissions. SAE Paper No. 012747.
Yao M., Zheng Z., Zhang B., Chen Z., 2004, The effect of PRF fuel octane number on HCCI opeation. SAE Paper No. 012292.
Yao M., Zheng Z., Liu H., 2009, Progress and recent trends in homogeneous charge compression ignition (HCCI) engines. Progress in Energy and Combustion Science, 35(5): 398-437.
Zhang C.H., Gonanaprakash G., Sobiesiak A., 2007, Experimental study and analysis on HCCI combustion of isooctane, ethanol and their blend. Transactions of CSICE, 25(5): 414-421.
Zhang C.H., Pan J.R., Tong J.J., Li J., 2011, Effects of intake temperature and excessive air coefficient on combustion characteristics and emissions of HCCI combustion. Procedia Environmental Sciences, 11: 1119-1127.
Zhang C.H., Xue L., Wang J., 2017, Experimental study of the influence of λ and intake temperature on combustion characteristics in an HCCI engine fueled with n-heptane. Journal of the Energy Instute, 87(2): 175-182.
Zhao H., 2007, HCCI and CAI engines for the automotive industry. Woodhead Publishing Limited, London, 78-118.
Zheng J., Yang W., Miller D.L., Cernansky N.P., 2002, A skeletal chemical kinetic model for the HCCI combustion process. SAE Technical Paper, 2002-01-0423.