Effect of fuel opening injection pressure and injection timing of hydrogen enriched rice bran biodiesel fuelled in CI engine

Fuel opening injection pressure and injection timing are important injection parameters, and they have a significant influence on engine combustion, performance, and emissions. The focus of this work is to improve the performance and emissions of single-cylinder diesel engines by using injection parameters in engines running with rice bran biodiesel 10% blend (RB10+H-2) and 20% blend (RB20+H-2) with a fixed hydrogen flow rate of 7 lpm. In addition, hydrogen and biodiesel are excellent alternatives to conventional fuels, which can reduce energy consumption and strict emission standards. The investigation is conducted for three different opening injection pressure of 220, 240, 260 bar, and four different injection timings of 20 degrees, 22 degrees, 24 degrees, and 26 degrees bTDC. Results indicate that the sample 'RB10+H-2' provides 3.32% higher BTE and reduces the fuel consumption by 13% as diesel fuel. The blend RB10+H-2 attributes a maximum cylinder pressure of 68.7 bar and a peak HRR value of 49 J/CA. Further, compared to diesel, RB10+H-2 blend emits lower CO, HC, and smoke opacity by 17%, 22%, and 16%, respectively. However, an almost 12% increase of nitrogen oxides for the RB10+H-2 blend is observed. However, with advanced injection timing and higher opening injection pressure, NOx emissions is slightly increased. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

Fuel injection pressure and timing are crucial parameters for engine performance and emissions. Using RB10+H-2 blend can increase fuel efficiency and reduce diesel consumption, resulting in lower CO, HC, and smoke opacity emissions, although slightly higher NOx emissions are observed.