Comparative Analysis of Two Injection Systems Fueled with Biodiesel

The paper presents experimental results concerning the fueling of two injection systems for D.I. Diesel engines with biodiesel fuel. The neat biodiesel (B100) was obtained from waste vegetable oil (collected from a local branch of McDonald's), using the base catalyzed method; diesel fuel was also used in order to test the injection equipments and obtain reference values. The in-line fuel injection pumps used during the tests were RO-PES4A90D410RS2240 and PES5MW55/320/RS/120403 (Bosch), with the corresponding high-pressure fuel lines and injectors. The injection equipment was mounted on a MIRKOZ test bed, equipped with pressure transducers, rotation angle transducer and a BOSCH injection rate meter. The tests were performed at different pump speeds and displacements of the injection pump control rack. The following injection characteristics were investigated: cyclic fuel delivery, injection duration, pressure wave propagation time, average injection rate, peak injection pressure. For the both types of injection equipment, cyclic fuel delivery, injection duration and peak injection pressure increased when biodiesel was used as fuel (compared to diesel fuel), while the average injection rate and pressure wave propagation time decreased.