Effect of injection parameters on the combustion and emission characteristics in a common-rail direct injection diesel engine fueled with waste cooking oil biodiesel

• Published in: Renewable energy Vol. 63; pp. 9 - 17
• Main Authors: Hwang, Joonsik, Qi, Donghui, Jung, Yongjin, Bae, Choongsik
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.03.2014; Elsevier
• Subjects: Applied sciences; Biodiesel; Combustion; Cooking; Cylinders; Diesel fuels; Emission; Energy; Energy. Thermal use of fuels; Engines and turbines; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Fatty acid; Heating; Natural energy; Time measurements; Waste cooking oil; Wastes; Emission; Waste cooking oil; Combustion; Biodiesel; Fatty acid; Renewable energy; Diesel fuel; Diesel engine; Biofuel
• ISSN: 0960-1481; 1879-0682
• DOI: 10.1016/j.renene.2013.08.051

The objective of this paper was to study the effects of the injection pressure and injection timing on the combustion and emission characteristics in a single-cylinder common-rail direct injection (CRDI) diesel engine fueled with waste cooking oil (WCO) biodiesel and commercial diesel fuel. The fuel property including fatty acid composition for the biodiesel were measured and compared with those of the conventional diesel fuel. The engine tests were conducted at two injection pressures (80 and 160 MPa) and different injection timings from −25 to 0 crank angle degree (CAD) after top dead center (aTDC) under two different engine loads. The results showed that the indicated specific fuel consumption (ISFC) with respect to the injection timings of the biodiesel was higher than that of the diesel fuel under all experimental conditions. The peak cylinder pressure and the peak heat release rate of the biodiesel were slightly lower, while the ignition delay was slightly longer under all operating conditions. In terms of emissions, the biodiesel had benefits in reduction of smoke, carbon monoxide (CO), hydrocarbon (HC) emissions especially with high fuel injection pressure. The nitrogen oxide (NOx) emissions of the biodiesel were relatively higher than those of the diesel under all experimental conditions. •Fatty acid composition of waste cooking oil (WCO) biodiesel was measured and analyzed.•Main properties of WCO biodiesel were measured and compared with those of diesel fuel.•Effect of fuel injection pressure and injection timing on the combustion was investigated.•Effect of fuel injection pressure and injection timing on the performance and emissions was studied.