Investigation of Waste Animal Fat Based Biodiesel Fuels’ Usage in a Common Rail Direct Injection Diesel Engine: Performance and Combustion Characteristics

In this study, biodiesel fuels were produced from waste chicken fat and waste fleshing oil with high free fatty acids, and those were tested in a common rail-DI diesel engine at constant engine speed of 2000 rpm and five different engine loads (50, 75, 100, 125 and 150 Nm). The effects of biodiesel fuels on the engine’s performance and combustion characteristics were investigated in comparison with petroleum-based diesel fuel (PBDF) which was the reference fuel. As compared to PBDF, brake specific fuel consumptions of biodiesels were higher but their thermal efficiencies were lower. The differences between performance characteristics became more pronounced with increasing engine load. In-cylinder pressures which were attained in pilot injection were higher with PBDF at all engine loads, while higher pressures were attained in main injection with biodiesel fuels at 125 and 150 Nm. The most critical differences between in-cylinder pressures and heat release rates were found at 125 Nm. The ignition delays varied with engine load; but for all test fuels it usually increased with engine load. While the combustion durations of biodiesel fuels were close to each other, PBDF’s combustion durations were relatively higher at all engine loads tested.

Atýk Hayvansal Yað Kökenli Biyomotorin Yakýtlarýn Ortak-Hat Direkt Püskürtmeli Bir Diesel Motorda Kullanýmýnýn Ýncelenmesi: Performans ve Yanma Karakteristikleri

Bu çalýþmada, yüksek serbest yað asidi içeriðine sahip atýk tavuk yaðý ve atýk deri yaðýndan biyomotorin yakýtlarý üretilmiþ ve ortak-hat direkt püskürtmeli bir diesel motorda 2000 d/d sabit motor devrinde ve beþ farklý motor yükünde (50, 75, 100, 125 ve 150 Nm) test edilmiþlerdir. Biyomotorinlerin motor performans ve yanma karakteristikleri üzerindeki etkileri referans yakýt olan petrol türevi diesel yakýtý (motorin) ile karþýlaþtýrýlmalý olarak incelenmiþtir. Motorine kýyasla; biyomotorin yakýtlarýn fren özgül yakýt tüketimleri daha yüksek, termik verimleri ise daha düþük olmuþtur. Performans karakteristikleri arasýndaki farklar motor yükü ile daha belirgin bir hal almýþtýr. Pilot püskürtmede motorin ile tüm motor yüklerinde daha yüksek basýnç deðerlerine ulaþýlýrken, 125 ve 150 Nm yük þartlarýnda ana püskürtmede biyomotorinler ile daha yüksek basýnçlar elde edilmiþtir. Silindir içi basýncý ve ýsý yayýlým oranlarý arasýndaki en kritik fark 125 Nm’de görülmüþtür. Tutuþma gecikmesi süreleri motor yükü ile farklýlýklar göstermiþ; fakat tüm yakýtlar için genellikle motor yükü ile birlikte artmýþtýr. Biyomotorin yakýtlarýn yanma süreleri birbirlerine yakýnken, tüm motor yüklerinde motorinin yanma süresi daha uzun olmuþtur.