شماره ركورد كنفرانس :
3288
عنوان مقاله :
Operating Range Extension of a Natural Gas Fueled PCCI Engine using Ozone
عنوان به زبان ديگر :
گسترش بازۀ عملكردي موتور PCCI گاز طبيعي با افزودني ازن
Author/Authors :
Ayat Gharehghani School of Mech. Eng. - Iran University of Science and Technology,Tehran , Mohammad Mahdi Salahi IOPTC ,Tehran , Vahid Esfahanian Vehicle, Fuel and Environment Research Institute (VFERI) - School of Mechanical Engineering - College of Engineering - University of Tehran , Amin Mahmoudzadeh Andwari Vehicle, Fuel and Environment Research Institute (VFERI) - School of Mechanical Engineering - College of Engineering - University of Tehran , Ali Salavati-Zadeh Vehicle, Fuel and Environment Research Institute (VFERI) - School of Mechanical Engineering - College of Engineering - University of Tehran
كليدواژه :
PCCI natural gas engine , numerical simulation , Ozone addition , detailed chemistry
عنوان كنفرانس :
دهمين همايش بين المللي موتورهاي درونسوز و نفت
چكيده فارسي :
يكي از مشكلات اساسي احتراق اشتعال تراكمي پيش آميخته، وجود احتراق ناقص مي باشد كه باعث توليد مقدار زيادي مونوكسيد كربن، بخصوص در مخلوط هاي بسيار رقيق، مي شود. اين موضوع، وقتي كه سوخت هاي با اكتان بالا، مانند گاز طبيعي، مورد استفاده قرار گيرد، چشم گيرتر خواهد بود. در اين مطالعۀ عددي، ازن بعنوان يك جزء شيميايي اكسيد كننده كه قابليت بهبود سينتيك شيميايي گاز طبيعي در حالت PCCI را داراست، مورد استفاده قرار گرفته است. نتايج نشان مي دهند كه با افزودن ازن، حتي مخلوط هاي بسيار رقيق (رقت 0.1 ) نيز قابليت احتراق مناسب و كامل را خواهد داشت و ميزان توليد CO بسيار كم خواهد شد. از طرف ديگر، افزودن ازن باعث پيشي زياد در احتراق و در نيتجه توليد كار منفي بيشتر و كاهش بازده موتور مي شود. در نتيجه، ميزان بهينه اي از ازن بايد افزوده شود تا فازبندي احتراق به درستي انجام گيرد.
چكيده لاتين :
One major drawback regarding premixed charge compression ignition (PCCI) engines is incomplete combustion accounting for high levels of carbon monoxide (CO) emission in ultra-lean operating conditions. This issue becomes even more crucial when fuels with high octane number, e.g. natural gas, are used. The present numerical investigation focused on the employment of ozone as oxidizing chemical species which can modify the chemical kinetic governing PCCI combustion of natural gas fueled engine. The numerical model is validated against the experimental data and then, the combustion characteristics and the engine emissions in conjunction with fuel equivalence ratio atvarious operating regions are discussed and compared. The results reveal that in the ultra-lean operating conditions (fuel equivalence ratio of 0.1), the PCCI engine with ozone addition is able to operate far from misfiring condition and shows a more complete combustion process and also produces less amounts of CO pollutant. On the other hand, higher ozone concentration causes more advancement in combustion phasing and therefore can decrease the engine thermal efficiency. To reach an optimum efficiency, the combustion phasing must be appropriately adjusted by adding suitable amounts of ozone.
