An Experimental Study Using Single and Multiple Injection Strategies in a Diesel Fuelled HCCI Engine with a Common Rail System 2009-26-0028

In this work, a single-cylinder, water-cooled engine was operated in the Homogenous Charge Compression Ignition (HCCI) mode with diesel as the fuel. Conventional as well as Common Rail Injection (CRI) systems were employed to study the influence of different injection strategies. The injection timing was fixed at 90° crank angle bTDC with the conventional injection system for HCCI operation based on brake thermal efficiency. With the conventional system, the BMEP range was 2.2 to 4.3 bar with a single-axial-hole injector. However, in this case, the brake thermal efficiency was about 30% lower than the CI mode. In the case of the CRI system, a specially developed single-hole nozzle with single and multiple injection strategies was used. Here, there was an improvement in the brake thermal efficiency and emissions were also under control. The BMEP range was only 1 to 3 bar. The results showed that by using multiple (3 pulses) injection, with the last pulse around the formation of the cool flame, significant improvements in HCCI operation could be obtained.