Experimental investigations on hydrogen biofueled reactivity controlled compression ignition engine using open ECU

This research work comprehensively investigates the different strategies on in-cylinder and after-treatment to reduce emissions in diesel engines under RCCI operation using ‘Fuel of Future’ Hydrogen and madhuca longifolia (ML) oil as primary and pilot fuels. The study used CRDI integrated with an open ECU system. Online injection timing/pressure variation, split injection, nano-emulsion, hydrogen-based RCCI mode, and cooled EGR techniques were implemented to extend the emissions to EURO-VI or BS-VI emission norms. The online optimized injection timing and pressure of ML operation improved the smoke emissions by 33% and 24%; HC emissions by 10% and 7%; CO emissions by 23% and 11%. With these optimized conditions, the pilot injection was splited as SPLIT-1 and 2 with three different spilt ratios (20:80, 30:70, 40:60). Also, 100 ppm graphene oxide emulsified with ML (NEM100) improved the smoke, HC, and CO emissions by 50%, 31%, and 35% respectively with optimized injection parameters. Amazingly, it was further reduced by 69%, 51%, and 64% under the hydrogen RCCI mode of operation. According to calculations and measurements, this research work successfully extended the emissions such as NOx, HC, and CO to 0.9, 1, and 1 g/kWh which are closer or equal to EURO-VI norms.