Effects of Partial Rcci Application of LPG on Performance, Combustion and Exhaust Emissions in a Diesel Engine Powered Generator

Abstract

In this study, engine performance, combustion and emissions of a diesel engine used for driving an electrical generator was investigated with LPG fumigation into the manifold of the engine as secondary fuel. Tests were carried out in 4 cylinders, 4 strokes water-cooled and direct-injection diesel engine generator. According to the test results; cylinder pressure, average gas temperature and peak values of heat release rate were increased as amount of LPG was increased. However, brake specific fuel consumption and mass fuel consumption were higher as well. Generally, with LPG addition, CO and HC emissions were found higher. Up to 40% LPG addition, CO2 emissions were lowered and over 40% LPG addition, CO2 emission increased. With increasing LPG ratio, there was a decrease in NOx emission values. On the other hand, generally, as LPG content was increased, O2 emissions were decreased significantly. Generally, the LPG usage of certain levels were found to be possible as secondary fuel in diesel engines. However, its usage in the engine up to certain levels resulted in considerable negative changes in performance, combustion and emissions changes. Over 55% LPG fumigation resulted in quite high flame velocity and propagation which eventually resulted in the accelerated cylinder pressure for per crank angle. This condition may be accepted as the starting of the knock. Therefore, only certain low amounts of LPG usage as secondary nonreactive fuel in diesel engine were found to be possible.

Dizel bir motorun reaktivite kontrollü sıkıştırma ateşlemeli bir motora dönüşümünde farklı oranlarda propan kullanımının ve yanma başlangıç zamanının performans, emisyon ve silindir içi yanma karakteristiklerine olan etkilerinin incelenmesi

“…Şekil 1. Silindir içi enerji dengesi (In-cylinder energy balance) [21] Eş. 1'de, silindir içerisindeki iç enerji değişimini, 𝑝 piston tarafından yapılan işi, yakıttan sağlanan enerjiyi, ∑ duvarlardan olan ısı kayıplarını, ℎ krank tarafına geçen entalpiyi, 𝑑𝑚 silindir içerisine emme manifoldundan geçen kütleyi, 𝑑𝑚 egzoz manifoldundan ayrılan kütleyi, ℎ ve ℎ giren ve çıkan kütlelerle oluşan entalpileri, 𝑞 yakıtın buharlaşma ısısını, f silindirden ayrılan buharlaşma ısı oranını ve 𝑚 ise buharlaşan yakıt kütle miktarını temsil etmektedir.…”

“…Sonuç olarak %10 oranında LPG eklenmesinin partikül madde, NOX ve CO düşürerek en uygun oran olduğu sonucuna ulaşmışlardır. (Aydın ve Aydın, [21]) yaptıkları çalışmada dizel jeneratör motoru emme manifoldundan ikincil bir enjeksiyon yardımı ile LPG ilavesinin performans, yanma karakteristiği ve emisyon davranışlarına etkilerini incelemişlerdir. Sonuç olarak ilgili motorda %55 LPG ilavesinden sonra vuruntu meydana geldiği saptanmıştır.…”