Experimental Investigations of Performance, Combustion and Emission Characteristics of Ethanol Fueled HCCI Engine

Year 2020, , 221 - 234, 20.03.2020

Alper Calam , Serdar Halis

https://doi.org/10.18185/erzifbed.608559

Abstract

In
this study, Ricardo Hydra test engine which has been converted from a four
stroke, single cylinder, port injection spark ignition (SI) engine to homogeneous
charged compression ignition (HCCI) engine was used. The effect of reference
heptane and heptane / ethyl alcohol mixtures (E15 and E25) on combustion,
engine performance and exhaust emissions was investigated experimentally. The
intake air inlet temperature is fixed at 60℃ and the engine speed is determined as 800 rpm.
In-cylinder pressure, heat release, start of combustion, CA50, combustion
duration, indicated thermal efficiency, indicated mean effective pressure (IMEP)
and exhaust emission results were investigated at different lambda values. Addition
of ethyl alcohol to heptane resulted in delayed and prolonged combustion. Also
this provided to slowing of the combustion. Consequently, the pressure rise
rate decreased and HCCI combustion was controlled. The highest indicated
thermal efficiency was found to be 49% when the lambda value was 2 and use of
E15 fuel. The highest IMEP was found to be 6,1 bar when the lambda value was 1,3
and use of E25 fuel. CO and HC emissions increased simultaneously with the
addition of ethyl alcohol to the heptane fuel. Compared to heptane, when the
E15 and E25 fuels are used, it can be stated that the low in-cylinder gas
temperatures are the main reason for the high emission values. It can be stated
that E15 fuel is the ideal fuel under suitable operating conditions via this
study.

Keywords

Low temperature combustion, HCCI, Performance, Ethanol, Fuel, Emission

Etil Alkol Yakıtlı HCCI Motorun Performans, Yanma ve Emisyon Özeliklerinin Deneysel Olarak İncelenmesi

Abstract

Bu
çalışmada dört zamanlı, tek silindirli, port enjeksiyonlu bir benzinli motordan
(SI) homojen dolgulu sıkıştırma ile ateşlemeli motora (HCCI) dönüşümü yapılmış
Ricardo Hydra test motoru kullanılmıştır. Referans heptan ve heptan/etil alkol
karışımlarının (E15 ve E25) yanma, motor performansı ve egzoz emisyonlarına
etkisi deneysel olarak incelenmiştir. Emme havası giriş sıcaklığı 60℃’de
sabitlenmiş ve motor hızı 800 rpm olarak belirlenmiştir. Farklı hava fazlalık
katsayısı (HFK) değerlerinde silindir içi basınç, ısı dağılımı, yanma
başlangıcı, CA50, yanma süresi, indike termik verim, indike ortalama efektif
basınç (IMEP) ve egzoz emisyon sonuçları incelenmiştir. Heptan yakıtına etil
alkol ilavesi yanmanın gecikmeye alınarak uzamasına neden olmuştur. Ayrıca
yanmanın yavaşlatılması sağlanmıştır. Buna bağlı olarak basınç artış oranı
azalarak HCCI yanma kontrol altına alınmıştır. En yüksek indike termik verim
E15 yakıtı kullanımında HFK’nın 2 olduğu şartlarda %49 olarak belirlenmiştir.
En yüksek IMEP E25 yakıtı kullanımında HFK’nın 1,3 olduğu şartlarda 6,1 bar
olarak tespit edilmiştir. CO ve HC emisyonları ise heptan yakıtına etil alkol
ilave edilmesi ile eş zamanlı olarak artış göstermiştir. Karışım yakıtları
kullanımında silindir içi gaz sıcaklıklarının heptana göre düşük olması, yüksek
emisyon değerlerinin temel nedeni olduğu ifade edilebilir. E15 yakıtının uygun
çalışma şartlardında ideal yakıt olduğu bu çalışma ile ifade edilebilir.

Keywords

Düşük sıcaklık yanması, HCCI, Performans, Etil alkol, Yakıt, Emisyon

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